High density carbon films for patterning applications

Abstract

The embodiments of the present disclosure generally relate to the deposition of high-density carbon films of high transparency for patterning applications. In one embodiment, a method for forming a carbon film on a substrate is provided. The method comprises the steps of flowing a hydrocarbon-containing gas mixture into a process chamber having a substrate positioned on an electrostatic chuck—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 sp3 atoms on the substrate, wherein the 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.

Description

Technology Field

[0001] The 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 carbon films for patterning applications. Background Technology

[0002] Integrated circuits have evolved into complex devices capable of containing millions of transistors, capacitors, and resistors on a single chip. The evolution of chip designs continuously requires faster networks and higher circuit densities. The demand for faster circuits with higher circuit densities imposes corresponding requirements on the process sequences used to manufacture integrated circuit components. For example, in process sequences using conventional photolithography techniques, an energy-sensitive resist layer is formed on a stack of material layers placed on a substrate. The energy-sensitive resist layer is exposed to an image of a pattern to form a photoresist mask. Subsequently, the mask pattern is transferred to one or more of the material layers in the stack using an etching process.

[0003] As pattern dimensions decrease, the thickness of the energy-sensitive resist is correspondingly reduced to control pattern resolution. These thin resist layers may be insufficient to mask the underlying material layers during pattern transfer operations due to attack by chemical etchants. Due to greater resistance to chemical etchants, a hard mask is commonly used between the energy-sensitive resist layer and the underlying material layers to enable pattern transfer. As critical dimensions (CD) decrease, current hard mask materials lack the desired etching selectivity compared to base materials (e.g., oxides and nitrides) and are often difficult to deposit.

[0004] Therefore, in the relevant technical field, improved hard mask layers and methods for depositing improved hard mask layers are required.

[0005] The 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 for forming a carbon film on a substrate is provided. The method comprises the steps of flowing a hydrocarbon-containing gas mixture into a process chamber having a substrate positioned on an electrostatic chuck—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 forming at least 60% hybridized sp on the substrate 3 To deposit a diamond-shaped carbon film containing atoms, the method includes the step of generating a plasma by applying a first RF bias to an electrostatic chuck, wherein the 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.

[0006] In another embodiment, the method comprises the steps of flowing a hydrocarbon-containing gas mixture into a processing 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 positioned opposite the electrostatic chuck on top of the electrostatic chuck to deposit a diamond-shaped 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 another embodiment, the method comprises the steps of: flowing a hydrocarbon-containing gas mixture into a processing volume of a process chamber having a substrate positioned on an electrostatic chuck—the substrate is maintained at a chamber pressure of about 5 mTorr to about 10 mTorr, and the hydrocarbon-containing gas mixture contains acetylene (C2H2); generating a plasma at the substrate level by applying a first RF bias to the electrostatic chuck to deposit a diamond-shaped carbon film on the substrate—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 on the diamond-shaped carbon film; etching the diamond-shaped carbon film in a pattern corresponding to the patterned photoresist layer; and depositing material into the etched portions of the diamond-shaped carbon film. Brief explanation of the drawing

[0008] In a manner that the features listed above in the present disclosure can be understood in detail, a more specific description of the embodiments briefly summarized above may be made with reference to the embodiments, some of which are illustrated in the accompanying drawings. However, it should be noted that the accompanying drawings are merely illustrative of typical embodiments of the present disclosure and should not be construed as limiting the scope of the present disclosure, as the present disclosure may allow for other equally valid embodiments.

[0009] FIG. 1a illustrates a schematic cross-sectional view of a deposition system that can be used to carry out the embodiments described herein.

[0010] FIG. 1b illustrates a schematic cross-sectional view of another deposition system that can be used to carry out the embodiments described herein.

[0011] FIG. 2 shows a schematic cross-sectional view of an electrostatic chuck that can be used in the apparatus of FIG. 1a and FIG. 1b for carrying out the embodiments described in this specification.

[0012] FIG. 3 illustrates a flowchart of a method for forming a diamond-shaped carbon layer on a film stack disposed on a substrate according to one or more embodiments of the present disclosure.

[0013] FIGS. 4a-4b illustrates one example of a sequence for forming a diamond-shaped carbon layer on a film stack formed on a substrate according to one or more embodiments of the present disclosure.

[0014] For ease of understanding, the same reference numerals have been used where possible to denote the same elements common to the drawings. It is considered that the elements and features of one embodiment may be advantageously incorporated into other embodiments without further mention. Specific details for implementing the invention

[0015] The following disclosure describes techniques for depositing diamond-like carbon films on a substrate. The embodiments described herein will be described below with reference to a PECVD process that can be executed using any suitable thin film deposition system. Examples of suitable systems are DXZ ® CENTURA, where a processing chamber can be used ® Systems, PRECISION 5000 ® Systems, PRODUCER ® Systems, PRODUCER ® GT TM Systems, PRODUCER ® XP Precision™ Systems, PRODUCER ® SE™ Systems, Sym3 ®It includes a processing chamber and a Mesa™ processing chamber, all of which are commercially available from Applied Materials, Inc., Santa Clara, California. Other tools capable of performing PECVD processes may also be configured to benefit from the embodiments described herein. Additionally, any system enabling the PECVD processes described herein may be used to make an advantage. The description of the apparatus described herein is illustrative and should not be interpreted or understood as limiting the scope of the embodiments described herein.

[0016] FIG. 1a illustrates a schematic example of a substrate processing system (132) that can be used to perform a diamond-shaped carbon layer deposition according to the embodiments described herein. The substrate processing system (132) includes a process chamber (100) coupled to a gas panel (130) and a controller (110). The process chamber (100) generally includes a top wall (124), a side wall (101), and a bottom wall (122) that define a processing volume (126). A substrate support assembly (146) is provided in the processing volume (126) of the process 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 made of aluminum, ceramic, and other suitable materials, such as stainless steel. The electrostatic chuck (150) can be moved vertically inside the process chamber (100) using a displacement mechanism (not shown).

[0017] A vacuum pump (102) is connected to a port formed at the bottom of the process chamber (100). The vacuum pump (102) is used to maintain a desired gas pressure within the process chamber (100). The vacuum pump (102) also vacuums process byproducts and post-processing gases from the process chamber (100).

[0018] A gas distribution assembly (120) having a plurality of openings (128) is positioned at the top of a process chamber (100) on an electrostatic chuck (150). The openings (128) of the gas distribution assembly (120) are used to introduce process gases into the process chamber (100). The openings (128) may have different sizes, numbers, distributions, shapes, designs, and diameters to enable the flow of various process gases for different process requirements. The gas distribution assembly (120) is connected to a gas panel (130) that allows various gases to flow into a processing volume (126) during processing. To enhance the thermal decomposition of process gases that cause the deposition of material on the top surface (191) of a substrate (190) positioned on the electrostatic chuck (150), a plasma is formed from the process gas mixture exiting the gas distribution assembly (120).

[0019] The gas distribution assembly (120) and the electrostatic chuck (150) can form a pair of spaced electrodes in the processing volume (126). To enable the generation of plasma between the gas distribution assembly (120) and the electrostatic chuck (150), one or more RF power sources (140) provide a bias potential to the gas distribution assembly (120) through an optional matching network (138). Alternatively, the RF power sources (140) and the matching network (138) may be coupled to the gas distribution assembly (120) or the electrostatic chuck (150), to both the gas distribution assembly (120) and the electrostatic chuck (150), or to an antenna (not shown) positioned outside the process 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, 100 MHz, or 162 MHz.

[0020] The controller (110) includes a central processing unit (112), memory (116), and support circuitry (114) used 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 environment. Software routines may be stored in memory (116), such as random access memory, read-only memory, a floppy or hard disk drive, or other forms of digital storage. Support circuitry (114) is coupled to the CPU (112) and may include a cache, clock circuitry, input / output systems, power supply, etc. Bidirectional communication between the various components of the substrate processing system (132) and the controller (110) is handled through a number of signal cables collectively referred to as signal buses (118), some of which are illustrated in FIG. 1A.

[0021] FIG. 1b illustrates a schematic cross-sectional view of another substrate processing system (180) that may be used to implement the 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 radially flow processing gases from a gas panel (130) through a sidewall (101) over the top surface (191) of a substrate (190). Additionally, the gas distribution assembly (120) shown in FIG. 1a is replaced by an electrode (182). The electrode (182) may be configured for secondary electron generation. In one embodiment, the electrode (182) is a silicon-containing electrode.

[0022] FIG. 2 illustrates a schematic cross-sectional view of a substrate support assembly (146) used in the processing systems of FIG. 1a and FIG. 1b, which can be used in the implementation of the embodiments described herein. Referring to FIG. 2, the electrostatic chuck (150) may include a heater element (170) suitable for controlling the temperature of a substrate (190) supported on the upper surface (192) of the electrostatic chuck (150). The heater element (170) may be embedded in the electrostatic chuck (150). The electrostatic chuck (150) may be heated resistively by applying current from a heater power source (106) to the heater element (170). The heater power source (106) may be coupled through an RF filter (216) to protect the heater power source (106) from RF energy. The current supplied from the heater power supply (106) is controlled by the controller (110) to control the heat generated by the heater element (170) so as to maintain 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) to about -50°C to about 350°C while depositing diamond-shaped carbon films on the substrate.

[0023] Referring to FIGS. 1a and 1b, a temperature sensor (172), such as a thermocouple, may be embedded in the electrostatic chuck (150) to monitor the temperature of the electrostatic chuck (150). The measured temperature is used by a controller (110) to control the power supplied to the heater element (170) to maintain the substrate at a desired temperature.

[0024] Referring again to FIG. 2, the electrostatic chuck (150) includes a chucking electrode (210) which may be a mesh of a conductive material. The chucking electrode (210) may be embedded in the electrostatic chuck (150). The chucking electrode (210) is coupled to a chucking power source (212) that electrostatically clamps a substrate (190) to an upper surface (192) of the electrostatic chuck (150) when energy is supplied.

[0025] The chucking electrode (210) may be configured as a monopolar or bipolar electrode, or may have other suitable arrangements. The chucking electrode (210) may be coupled to the chucking power supply (212) through an RF filter (214), which provides DC (direct current) 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 plasma within the process chamber (100) from damaging the electrical equipment. The electrostatic chuck (150) may be made of a ceramic material such as AlN or Al2O3.

[0026] A power application system (220) is coupled to a substrate support assembly (146). The power application system (220) may include a heater power supply (106), a chucking power supply (212), a first RF (radio frequency) power supply (230), and a second RF power supply (240). Embodiments of the power application system (220) may further include a controller (110) and a sensor device (250) that communicates with both the controller (110) and the first RF power supply (230) and the second RF power supply (240). The controller (110) may also be used to control plasma from a processing 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).

[0027] As previously described, the electrostatic chuck (150) includes a chucking electrode (210) which, in one aspect, functions to chuck a substrate (190) and also functions as a first RF electrode. The electrostatic chuck (150) may also include a second RF electrode (260) and can adjust the plasma by applying RF power together with the chucking electrode (210). A first RF power source (230) may be coupled to the second RF electrode (260), while a second RF power source (240) may be coupled to the chucking electrode (210). A first matching network and a second matching network may be provided to the first RF power source (230) and the second RF power source (240), respectively. The second RF electrode (260) may be a solid metal plate of a conductive material or a mesh of a conductive material.

[0028] The first RF power source (230) and the second RF power source (240) may 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) may independently generate power at frequencies of 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). RF power from one or both of the first RF power source (230) and the second RF power source (240) may be changed to adjust the plasma.

[0029] Generally, the systems described with respect to FIGS. 1a, 1b, and 2 may 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 essentially amorphous and have a high sp⁻¹. 3 It has a carbon content (e.g., diamond type). The as-deposited diamond-like carbon layer has an absorption coefficient or k-value (K at 633 nm) of less than 0.1, e.g. 0.09; a density (g / cc) exceeding 1.8 g / cc, e.g. approximately 2.0 g / cc or greater, approximately 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) exceeding 2.0, e.g. approximately 2.0 to about 3.0, e.g. 2.3; a stress (MPa) of less than about -100 MPa, e.g. about -100 MPa to about -100 MPa, e.g. about -550 MPa; and an elasticity of about 150 GPa or greater, e.g. about 200 to about 400 GPa. It has a modulus (GPa). In various embodiments of the present disclosure, the diamond-like carbon layer immediately after deposition has sp 3 At least 40% of hybrid carbon atoms, for example, about 60% or more, for example sp 3It can contain about 90% hybrid carbon atoms. The diamond-like carbon layer immediately after deposition can have a thickness of about 5 Å to about 20,000 Å.

[0030] A diamond-like carbon layer having the above characteristics can be formed using the following exemplary deposition process parameters. The substrate temperature may be in the range of about -50°C to about 350°C (e.g., about -10°C to about 20°C). The chamber pressure may be in the range of 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 may be about 10 sccm to about 1,000 sccm (e.g., about 100 sccm to about 200 sccm). The flow rate of the diluent gas may be individually in the range of about 50 sccm to about 5,000 sccm (e.g., about 50 sccm to about 200 sccm). Table 1 below illustrates exemplary deposition process parameters performed on a 300 mm substrate in a deposition chamber available from Applied Materials, Inc., Santa Clara, California. deposition parameters Exemplary range Exemplary range Exemplary range Temperature (°C) -50 to 350℃ 10 to 100℃ 10 to 50℃ Pressure (Torr) 0.5mTorr-10Torr 2mTorr-50mTorr 2mTorr-10mTorr 1st RF power (60 MHz) 100-3000 watts 2,000-3,000 watts 2000 watts 2nd RF power (2 MHz) 200-2000 watts 800-1200 watts 1000 watts interval 1,000 to 15,000 mils 6,000 to 12,000 mils 8,000 to 12,000 mils C 2 H 2 fluid 10-1000sccm 100-200 sccm 150sccm He fluid 50-5000sccm 50-100 sccm 100sccm

[0031] FIG. 3 illustrates a flowchart of a method (300) for forming a diamond-shaped carbon layer on a film stack disposed on a substrate according to one embodiment of the present disclosure. The diamond-shaped carbon layer formed on the film stack may be used, for example, as a hard mask for forming stepped structures on the film stack. FIGS. 4a and 4b are schematic cross-sectional views illustrating a sequence for forming a diamond-shaped carbon layer on a film stack disposed on a substrate according to the method (300). It should also be understood that the operations illustrated in FIG. 3 may be performed simultaneously and / or in a different order than the illustrated order.

[0032] This method (300) begins in operation (310) by positioning a substrate, such as the substrate (400) shown in FIG. 4a, in a process chamber, such as the process chamber (100) shown in FIG. 1a or FIG. 1b. The substrate (400) may be the substrate (190) shown in FIG. 1a, FIG. 1b and FIG. 2. The substrate (400) may be positioned on the upper surface (192) of an electrostatic chuck, for example, an electrostatic chuck (150). The substrate (400)—where a film stack (404) is placed on the substrate (400)—may be a silicon-based material or any suitable insulating material, conductive material or semiconductor material that can be used to form structures (402), such as stepped structures, with the film stack (404) as needed.

[0033] As illustrated in the exemplary embodiment shown in FIG. 4a, the substrate (400) may have a substantially flat surface, an uneven surface, or a substantially flat surface on which a structure is formed. A film stack (404) is formed on the substrate (400). In one embodiment, the film stack (404) may be used to form a gate structure, a contact structure, or an interconnect structure in a front-end or back-end process. This method (300) may be performed on the film stack (404) to form stepped structures used in memory structures, such as NAND structures, within the film stack (404). In one embodiment, the substrate (400) is crystalline silicon (e.g., Si <100> or Si <111> The substrate (400) may be a material such as SOI (silicon on insulator), carbon-doped silicon oxides, silicon nitride, doped silicon, germanium, gallium arsenide, glass, or sapphire, which are silicon oxide, modified silicon, silicon germanium, doped or undoped polysilicon, doped or undoped silicon substrates, and patterned or unpatterned substrates. The substrate (400) may have rectangular or square panels as well as various dimensions such as substrates of 200 mm, 300 mm, and 450 mm or other diameters. Unless otherwise noted, the embodiments and examples described herein are performed for substrates having a diameter of 200 mm, 300 mm, or 450 mm. In an embodiment where an SOI structure is used in the substrate (400), the substrate (400) may include a buried dielectric layer disposed on a silicon crystalline substrate. In an embodiment illustrated herein, the substrate (400) may be a crystalline silicon substrate.

[0034] In one embodiment, the film stack (404) disposed on the substrate (400) may have a plurality of vertically stacked layers. The film stack (404) is repeatedly formed as film stacks (408a1, 408a2, 408a3,……, 408a nThe first layer (as described) and (408b1, 408b2, 408b3,……, 408b n It may include pairs comprising a second layer (as illustrated as). These pairs may include alternating (408a1, 408a2, 408a3,……, 408a n The first layer (as depicted) and (408b1, 408b2, 408b3,……, 408b n It includes a second layer (as depicted), which is repeatedly formed until a desired number of pairs of first and second layers is reached.

[0035] The membrane stack (404) may be part of a semiconductor chip, such as a three-dimensional memory chip. FIGS. 4a - FIGS. 4b shows (408a1, 408a2, 408a3,……, 408a n The first layers (as described) and (408b1, 408b2, 408b3,……, 408b n It is noted that although three repeating layers of the second layer (as illustrated) are illustrated, any desired number of repeating pairs of the first and second layers may be used as needed.

[0036] In one embodiment, the film stack (404) may be used to form a plurality of gate structures for a three-dimensional memory chip. First layers (408a1, 408a2, 408a3, ……, 408a) formed by the film stack (404). n ) may be a first genome layer, and the second layers (408b1, 408b2, 408b3,……, 408b n ) may be a second dielectric layer. Suitable dielectric layers comprising silicon oxide, silicon nitride, silicon oxynitride, silicon carbide, silicon oxycarbide, titanium nitride, a composite of oxide and nitride, at least one oxide layer sandwiching the nitride layer, and combinations thereof are first layers (408a1, 408a2, 408a3,……, 408a n) and the second layer (408b1, 408b2, 408b3,……, 408b n It can be used to form ). In some embodiments, the dielectric layers may be high-k materials having a dielectric constant greater than 4. Suitable examples of high-k materials include, among others, hafnium dioxide (HfO2), zirconium dioxide (ZrO2), hafnium silicon oxide (HfSiO2), hafnium aluminum oxide (HfAlO), zirconium silicon oxide (ZrSiO2), tantalum dioxide (TaO2), aluminum oxide, aluminum-doped hafnium dioxide, bismuth strontium titanium (BST), and platinum zirconium titanium (PZT).

[0037] 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 the first layers (408a1, 408a2, 408a3,……, 408a n They are silicon nitride layers or polysilicon layers disposed on ). In one embodiment, the first layers (408a1, 408a2, 408a3,……, 408a n The thickness of ) can be controlled to about 50 Å to about 1000 Å, for example, about 500 Å, and each of the second layers (408b1, 408b2, 408b3,……, 408b n The thickness of the film stack (404) can be controlled to be about 50 Å to about 1000 Å, for example, about 500 Å. The film stack (404) can have a total thickness of about 100 Å to about 2000 Å, and may vary as technology advances.

[0038] It is noted that the diamond-shaped carbon layer can be formed on any surface or any part of the substrate (400) that may or may not have a film stack (404) present on the substrate (400).

[0039] 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) through the chucking electrode (210). The chucking electrode (210) can communicate electronically with a chucking power supply (212) that supplies a biasing voltage to the chucking electrode (210). In one embodiment, the chucking voltage is about 10 volts to about 3000 volts.

[0040] During operation (320), the process pressure of the processing volume can be maintained at about 0.1 mTorr to about 10 Torr (e.g., about 0.5 mTorr to about 15 mTorr), and the processing temperature and / or substrate temperature can be maintained at about -50°C to about 350°C (e.g., about -10°C to about 20°C).

[0041] In operation (330), a hydrocarbon-containing gas mixture is flowed into a processing volume (126). The hydrocarbon-containing gas mixture may be flowed from a gas panel (130) into the processing volume (126) via a gas distribution assembly (120) or through a side wall (101). The hydrocarbon-containing gas mixture may contain at least one hydrocarbon compound. The hydrocarbon-containing gas mixture may further contain an inert gas, a diluent gas, or any combination thereof. In some embodiments, the chucking voltage supplied during operation (320) is maintained during operation (330). In some embodiments, the process conditions set during operation (320) are maintained during operation (330).

[0042] In one embodiment, the hydrocarbon compound is a gaseous hydrocarbon. In one embodiment, the hydrocarbon compound is of the general formula C x H yIt has, where x ranges from 1 to 20 and y ranges from 1 to 20. Suitable hydrocarbon compounds are, for example, C2H2, C3H6, CH4, C4H8, 1,3-dimethyladamantan, bicyclo[2.2.1]hepta-2,5-diene(2,5-norbornedine), adamantane(C 10 H 16 ), Nowonen (C7H 10 Includes ), or combinations thereof.

[0043] 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 (H2), nitrogen (N2), ammonia (NH3), or any combination thereof. In one embodiment, the diluent gas comprises a combination of Ar, He, and N2. In one embodiment, the diluent gas comprises a combination of Ar, He, and H2.

[0044] 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) may be supplied within the processing volume (126) together with the hydrocarbon-containing gas mixture. Other inert gases such as nitrogen (N2) and nitric oxide (NO) may also be used to control the density and deposition rate of the diamond-like carbon layer.

[0045] In operation (340), as illustrated in FIG. 4b, plasma is generated at the substrate level to form a diamond-shaped carbon film on the film stack. The plasma can be generated by applying a first RF bias to an electrostatic chuck. The first RF bias may be about 10 watts to about 3000 watts at a frequency of 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 about 1500 watts to about 2500 watts (e.g., 1800-2200 watts) and at a frequency of about 40 MHz or higher. In one embodiment, a first RF bias is provided to the electrostatic chuck (150) through a second RF electrode (260). The second RF electrode (260) can electronically communicate with a first RF power source (230) that supplies a biasing voltage to the second RF electrode (260). The first RF power source (230) can generate power 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).

[0046] In some embodiments, the operation (340) further comprises applying a second RF bias to the electrostatic chuck to independently control the ion density and ion energy to modulate the film stress. The second RF bias may be from about 10 watts to about 3000 watts 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 of about 800 watts to 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) through the chucking electrode (210). The chucking electrode (210) can electronically communicate with a second RF power source (240) that supplies a biasing voltage to the chucking electrode (210). In one embodiment, the second RF bias is provided with a power of about 10 watts to about 3000 watts. In one embodiment, the second RF bias is provided with a power of about 800 watts to about 1200 watts. In one embodiment, the chucking voltage supplied in operation (320) is maintained during operation (340).

[0047] In some embodiments that may be combined with any other embodiments of the present disclosure, during operation (340), a first RF bias may be provided to the substrate (400) through the chucking electrode (210), and a second RF bias may be provided to the substrate (400) through the second RF electrode (260).

[0048] In some embodiments that may be combined with any other embodiments of the present disclosure, during operation (340), a first RF bias may be provided to a gas distribution assembly (120) or an electrode (182), and a second RF bias may be provided to a substrate (400) through a second RF electrode (260) or a chucking electrode (210). In this case, the first RF bias applied to the gas distribution assembly (120) or the electrode (182) may have a high frequency, and the second RF bias applied to the second RF electrode (260) or the chucking electrode (210) may have a low frequency.

[0049] Various combinations of power levels and frequencies may be used by the first RF bias and the second RF bias. In some embodiments, the first RF bias may be about 2000 watts at about 40 MHz, 60 MHz, or 162 MHz, and the second RF bias may be about 1000 watts at 350 kHz. In some embodiments, the first RF bias may be about 2000 watts at 40 MHz, 60 MHz, or 162 MHz, and the second RF bias may be about 1000 watts at 2 MHz. In some embodiments, the first RF bias may be about 2000 watts at about 40 MHz, 60 MHz, or 162 MHz, and the second RF bias may be about 1000 watts at 13.56 MHz.

[0050] In some additional embodiments that may be combined with any other embodiments of the present disclosure, during operation (340), a first RF bias may be provided to the substrate (400) through the chucking electrode (210), a second RF bias may be provided to the substrate (400) through the second RF electrode (260), and a third RF bias may be provided to the gas distribution assembly (120) or the electrode (182). In such cases, the first RF bias and the second RF bias may be any combination of frequencies and powers discussed in the present disclosure, and the third RF bias may be configured to have the same power and frequency as the power and frequency of the first or second RF bias discussed in the specification.

[0051] In some embodiments, after a diamond-shaped carbon layer (412) is formed on a substrate during operation (340), the diamond-shaped carbon layer (412) is exposed to hydrogen radicals. In some embodiments, the diamond-shaped 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 transferred to the processing area. Although not bound by theory, exposing the diamond-shaped carbon layer to hydrogen radicals is sp 2 This leads to the selective etching of hybrid carbon atoms, resulting in the sp of the film 3 It is believed to increase the hybrid carbon atom fraction, thereby increasing etching selectivity.

[0052] In operation (350), after a diamond-shaped carbon layer (412) is formed on the substrate, the substrate is de-chucked. During operation (350), the chucking voltage is cut off. Reactive gases are cut off and optionally purged from the processing chamber. In one embodiment, the RF power is reduced during operation (350) (e.g., ~200 W). When the substrate is de-chucked from the electrostatic chuck, the remaining gases are purged from the processing chamber. The processing chamber is pumped down and the substrate is moved over the lift pins and transferred out of the process chamber.

[0053] After the diamond-shaped carbon layer (412) is formed on the substrate, the diamond-shaped 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-shaped carbon layer (412) can be patterned using standard photoresist patterning techniques.

[0054] The following non-limiting examples are provided to further illustrate the embodiments described herein. However, the examples are not intended to be all-encompassing and are not intended to limit the scope of the embodiments described herein. In one embodiment, a low-stress, high-density diamond-like carbon film of the present disclosure was fabricated by flowing 150 sccm C2H2 and 100 sccm He as process gases at a temperature of 10°C while applying 2000 watts RF (60 MHz) power across a substrate pedestal (electrostatic chuck) in a CVD reactor using Ar and / or He as diluent gases. A comparison between the resulting diamond-like carbon film, amorphous carbon reference films, and diamond-like carbon films formed by PVD is illustrated in Table 2 below. Membrane type Amorphous carbon film criteria PVD diamond-shaped carbon film standards PECVD diamond-shaped carbon membrane Density (g / cc) 1.75 2.52 1.83 Stress (MPa) -50 -350 -600 n @ 633㎚ 2.07 >2.3 2.37 k @ 633㎚ 0.63 >0.5 0.09 sp 3 % <10% ~50% ~60% Elastic modulus / hardness (㎬) 53 / 5.8 231 / 19 180 / 20

[0055] Accordingly, methods and apparatus for forming a high-transparency diamond-shaped carbon hard mask layer that can be used to form stepped structures for manufacturing three-dimensional stacking of semiconductor devices are provided. By using a diamond-shaped hard mask layer having desired rigid 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 chip devices in applications for three-dimensional stacking of semiconductor devices can be improved.

[0056] Although the foregoing describes embodiments of the present disclosure, other embodiments and additional embodiments of the present disclosure may be devised without departing from the basic scope of the present disclosure, and the scope of the present disclosure is determined by the following claims.

Claims

Claim 1 A method for forming a carbon film on a substrate, comprising the steps of: flowing a hydrocarbon-containing gas mixture into a process chamber having a substrate positioned on an electrostatic chuck — wherein the electrostatic chuck comprises a first RF (radio frequency) electrode and a second RF electrode disposed within the electrostatic chuck, and the substrate is maintained at a temperature of -50°C to 350°C —; and generating a plasma by applying a first RF bias to the first RF electrode of the electrostatic chuck to deposit a diamond-shaped carbon film on the substrate. Claim 2 A method for forming a carbon film on a substrate, wherein the step of generating the plasma in claim 1 further comprises the step of applying a second RF bias to the second RF electrode of the electrostatic chuck. Claim 3 A method for forming a carbon film on a substrate, wherein the second RF bias is provided at a power of 800 to 1200 watts and a frequency of 350 kHz to 13.56 MHz. Claim 4 A method for forming a carbon film on a substrate, wherein, in paragraph 2, the first RF bias is provided at a power of 10 to 3000 watts and a frequency of 350 kHz or higher, and the second RF bias is provided at a power of 10 to 3000 watts and a frequency of 350 kHz or higher. Claim 5 A method for forming a carbon film on a substrate, wherein the substrate is maintained at a temperature of -10°C to 20°C in accordance with claim 1. Claim 6 In claim 1, the hydrocarbon-containing gas mixture comprises C2H2, C3H6, CH4, C4H8, 1,3-dimethyladamantan, bicyclo[2.2.1]hepta-2,5-diene(2,5-norbornadine), and adamantan (C 10 H 16 ), Nowonen (C7H 10 A method for forming a carbon film on a substrate comprising a hydrocarbon precursor including ), or a combination thereof. Claim 7 A method for forming a carbon film on a substrate, wherein the hydrocarbon-containing gas mixture comprises a dilution gas including He, Ar, Xe, N2, H2, or any combination thereof. Claim 8 A method for forming a carbon film on a substrate, wherein the hydrocarbon-containing gas mixture is flowed into the process chamber through a gas panel disposed on the side wall of the process chamber in accordance with claim 1. Claim 9 A method for forming a carbon film on a semiconductor substrate, comprising the steps of: flowing a mixture of a hydrocarbon-containing gas and a diluent gas into a process chamber having the semiconductor substrate positioned on an electrostatic chuck—wherein the volume ratio of the diluent gas to the hydrocarbon-containing gas is 1:4 or greater; and generating a plasma by applying a first RF bias to a first electrode positioned on the electrostatic chuck and applying a second RF bias to a second electrode positioned on the electrostatic chuck to deposit a diamond-shaped carbon film on the semiconductor substrate, wherein the semiconductor substrate is maintained at a temperature of -50°C to 350°C. Claim 10 A method for forming a carbon film on a semiconductor substrate according to claim 9, wherein the first RF bias is provided at a frequency of 13.56 MHz or less, and the semiconductor substrate is maintained at a temperature of -10°C to 20°C. Claim 11 A method for forming a carbon film on a semiconductor substrate, wherein the second RF bias is provided at a frequency of 60 MHz and a power of 1500 watts to 2500 watts. Claim 12 In claim 9, the hydrocarbon-containing gas is C2H2, C3H6, CH4, C4H8, 1,3-dimethyladamantan, bicyclo[2.2.1]hepta-2,5-diene(2,5-norbornadine), adamantan(C 10 H 16 ), Nowonen (C7H 10 A method for forming a carbon film on a semiconductor substrate, comprising ), or a combination thereof. Claim 13 A method for forming a carbon film on a semiconductor substrate according to claim 9, wherein the diluent gas comprises He, Ar, Xe, N2, H2, or any combination thereof. Claim 14 A method for forming a carbon film on a semiconductor substrate, wherein the step of generating the plasma in claim 9 further comprises the step of applying a third RF bias to a third electrode disposed opposite to the electrostatic chuck on the upper part of the electrostatic chuck. Claim 15 A method for forming a carbon film on a semiconductor substrate, wherein the third RF bias is provided at a power of 10 watts to 3000 watts and a frequency of 350 kHz to 162 MHz. Claim 16 A method for processing a substrate, comprising the steps of: flowing a hydrocarbon-containing gas mixture into a processing volume of a process chamber having said substrate positioned on an electrostatic chuck — said substrate comprises a film stack having a first dielectric layer and a second dielectric layer disposed on the first dielectric layer —; applying a first RF bias to the electrostatic chuck to generate a plasma to deposit a diamond-shaped carbon film on said substrate — said diamond-shaped carbon film has an elastic modulus of 200 GPa to 400 GPa —; forming a patterned photoresist layer over said diamond-shaped carbon film; etching said diamond-shaped carbon film in a pattern corresponding to said patterned photoresist layer to create etched portions; and depositing a material in said etched portions of said diamond-shaped carbon film. Claim 17 A method for processing a substrate according to claim 16, wherein the step of generating the plasma further comprises the step of applying a second RF bias to the electrostatic chuck. Claim 18 In claim 16, a method for processing a substrate in which the diamond-shaped carbon film is used as a sublayer in an EUV (extreme ultraviolet) lithography process. Claim 19 A method for processing a substrate according to claim 16, wherein the hydrocarbon-containing gas mixture further comprises a dilution gas comprising He, Ar, Xe, N2, H2, or any combination thereof. Claim 20 A method for processing a substrate according to claim 19, wherein the hydrocarbon-containing gas mixture flows into the process chamber through a gas panel disposed on the side wall of the process chamber.

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