JP7704828B2 - Method for producing densely doped carbon films for hardmasks and other patterning applications - Patents.com - Google Patents

Description

[0001] 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.

Description of the Related Art [0002] Integrated circuits have evolved into complex devices that may contain 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 materials used in the fabrication of such integrated circuits. In particular, as the dimensions of integrated circuit components shrink to sub-micron scale, it is now necessary to use not only conductive materials with low resistivity, but also insulating materials with low dielectric constants to obtain adequate electrical performance from such components.

[0003] The demand for greater integrated circuit density also places 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 over a material layer of a stack disposed on a substrate. The energy sensitive resist layer is exposed to an image of a pattern to form a photoresist mask. An etching process is then used to transfer the mask pattern to one or more material layers of the stack. A chemical etchant used in the etching process is selected to have a higher etch selectivity for the material layer of the stack than for the energy sensitive resist mask. That is, the chemical etchant etches the one or more layers of the material stack at a much faster rate than the energy sensitive resist. The etch selectivity for one or more material layers of the stack over the resist prevents the energy sensitive resist from being worn out before the pattern transfer is complete.

[0004] As pattern dimensions shrink, the thickness of the energy sensitive resist is correspondingly reduced to control pattern resolution. Such thin resist layers may be insufficient to mask the underlying material layer during the pattern transfer process due to erosion by chemical etchants. An intermediate layer called a hard mask (e.g., silicon oxynitride, silicon carbide, or carbon film) is often used between the energy sensitive resist layer and the underlying material layer to facilitate pattern transfer by being more resistant to chemical etchants. Hard mask materials that have both high etch selectivity and fast deposition rates are needed. As critical dimensions (CDs) shrink, existing hard mask materials lack the desired etch selectivity compared to the underlying materials (e.g., oxides and nitrides) and are often difficult to deposit.

[0005] Thus, there is a need in the art for improved hardmask layers and methods for depositing improved hardmask layers.

[0006] 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 or more embodiments, a method of processing a substrate includes flowing a deposition gas including one or more hydrocarbon compounds and one or more dopant compounds into a processing space of a processing chamber having a substrate disposed on an electrostatic chuck, the processing space being maintained at a pressure between about 0.5 mTorr and about 10 Torr. The method also includes generating a plasma at the substrate by applying a first RF bias to the electrostatic chuck to deposit a doped diamond-like carbon film on the substrate, the doped diamond-like carbon film having a density greater than 2 g/cc and a compressive stress less than -500 MPa.

[0007] In some embodiments, a method of processing a substrate includes flowing a deposition gas including one or more hydrocarbon compounds and one or more dopant compounds into a processing space of a processing chamber having a substrate disposed on an electrostatic chuck, the electrostatic chuck having a chucking electrode and an RF electrode separated from the chucking electrode, and the processing space being maintained at a pressure between about 0.5 mTorr and about 10 Torr. The method also includes generating a plasma at the substrate by applying a first RF bias to the RF electrode and a second RF bias to the electrostatic chuck to deposit a doped diamond-like carbon film on the substrate. The doped diamond-like carbon film has a density of greater than about 2 g/cc to about 12 g/cc and a stress of about -600 MPa to about -300 MPa. The doped diamond-like carbon film includes between about 50 atomic percent (at%) and about 90 at% sp ³ hybridized carbon atoms.

[0008] In another embodiment, a method of processing a substrate includes flowing a deposition gas including one or more hydrocarbon compounds and one or more dopant compounds into a processing space of a processing chamber having a substrate disposed on an electrostatic chuck. The electrostatic chuck has a chucking electrode and an RF electrode separated from the chucking electrode, and the processing space is maintained at a pressure between about 0.5 mTorr and about 10 Torr. The method also includes generating a plasma at the substrate by applying a first RF bias to the RF electrode and a second RF bias to the chucking electrode to deposit a doped diamond-like carbon film on the substrate, the doped diamond-like carbon film having a density of greater than 2 g/cc to about 12 g/cc and a stress of about -500 MPa to about -300 MPa. The method further includes forming a patterned photoresist layer over the doped diamond-like carbon film, etching the doped diamond-like carbon film in a pattern corresponding to the patterned photoresist layer, and etching the pattern into a substrate.

[0009] In one or more embodiments, a film for use as an underlayer for extreme ultraviolet ("EUV") lithography processing is provided having a content of ^sp3 hybridized carbon atoms of about 40% to about 90% based on the total amount of carbon atoms in the film, about 0.1 at% to about 20 at% of one or more dopants, and an elastic modulus of about 150 GPa or more to about 400 GPa.

[0010] In order that the features of the present disclosure may be understood in detail, a more particular description of the present disclosure briefly summarized above may be obtained by reference to implementations, some of which are illustrated in the accompanying drawings. It should be noted, however, that since the present disclosure may admit of other equally effective embodiments, the accompanying drawings depict only typical embodiments of the present disclosure and are therefore not to be considered as limiting the scope of the present invention.

FIG. 1 shows a schematic cross-sectional view of a deposition system that can be used to practice embodiments described herein. FIG. 1 shows a schematic cross-sectional view of another deposition system that can be used to practice embodiments described herein. FIG. 2 shows a schematic cross-sectional view of an electrostatic chuck that may be used in the apparatus of FIGS. 1A and 1B that may be used to practice embodiments described herein. 1 illustrates a flow diagram of a method for forming a doped diamond-like carbon film on a film stack disposed on a substrate in accordance with one or more embodiments of the present disclosure. 1 illustrates a sequence for forming a doped diamond-like carbon film on a film stack formed on a substrate, in accordance with one or more embodiments of the present disclosure. 1 illustrates a sequence for forming a doped diamond-like carbon film on a film stack formed on a substrate, in accordance with one or more embodiments of the present disclosure. FIG. 1 illustrates a flow diagram of a method of using doped diamond-like carbon films in accordance with one or more embodiments of the present disclosure.

[0017] For ease of understanding, identical reference numbers have been used, where possible, to designate identical elements common to the figures. It is believed that elements and features of one embodiment may be beneficially incorporated in other embodiments without further description.

[0018] Embodiments provided herein relate to doped diamond-like carbon films and methods for depositing or forming doped diamond-like carbon films on a substrate. Specific details are presented in the following description and in FIGS. 1A-5 to provide a thorough understanding of various embodiments of the present disclosure. Other details describing well-known structures and systems often associated with plasma processing and deposition of doped diamond-like carbon films are not set forth in the following disclosure to avoid unnecessarily obscuring the description of the various implementations.

[0019] Many of the details, dimensions, angles, and other features shown in the drawings are merely illustrative of particular implementations. Thus, other implementations may have other details, components, dimensions, angles, and features without departing from the spirit or scope of the disclosure. In addition, further embodiments of the disclosure may be practiced without some of the details described below.

[0020] The embodiments described herein are described below with reference to chemical vapor deposition (PE-CVD) processes that can be performed using any suitable thin film deposition system. Examples of suitable systems include the DXZ® processing chamber, the PRECISION5000® system, the PRODUCER® system, the PRODUCER® GT™ system, the PRODUCER® XP Precision™ system, the PRODUCER® SE™ system, the Sym3® processing chamber, and the CENTURA® system that can use the Mesa™ processing chamber, all of which are available from Applied Materials Inc., Santa Clara, Calif. Other tools capable of performing PE-CVD processes can also be adapted to benefit from the embodiments described herein. Additionally, any system that enables the CVD processes described herein may be used to advantage. Any apparatus descriptions described herein are exemplary and should not be understood or construed as limiting the scope of the embodiments described herein.

[0021] Current hardmask applications for memory and other devices mainly utilize thick carbon films (e.g., about 300 nm to about 1.5 microns) that are amorphous in nature, but their etch selectivity is no longer sufficient to meet the increasingly stringent requirements and high aspect ratio etching of upcoming nodes. To achieve higher etch selectivity, the density and Young's modulus of the film need to be improved. One of the main challenges in achieving higher etch selectivity and improved Young's modulus is that the high compressive stress of such films results in high wafer/substrate bowing, making them unsuitable for applications. Thus, there is a need for (diamond-like) carbon films with high etch selectivity and low stress (e.g., < -500 MPa) and high density and elastic modulus (e.g., higher ^sp3 content, more diamond-like).

[0022] The embodiments described herein include an improved method for producing doped diamond-like carbon films having high density (e.g., >2 g/cc), high modulus (e.g., >150 GPa), and low stress (e.g., < -500 MPa). The doped diamond-like carbon films produced by the embodiments described herein are amorphous in nature and have higher etch selectivity with higher modulus (e.g., >150 GPa) along with lower stress than current patterned films. The doped diamond-like carbon films produced by the embodiments described herein have not only low stress but also high sp ³ carbon content. In general, the deposition processes described herein are also fully compatible with current integration schemes for hardmask applications.

[0023] In one or more embodiments, the doped diamond-like carbon films described herein may be formed by CVD, such as plasma enhanced chemical vapor deposition (CVD) and/or thermal CVD processes, using a deposition gas that includes one or more hydrocarbon compounds and one or more dopant compounds. Exemplary hydrocarbon compounds may _be or include ethylene or acetylene ( _C2H2 ), propene _{( C3H6} ), methane ( _CH4 ), butene _{( C4H8} ), 1,3-dimethyladamantane, bicyclo[2.2.1]hepta-2,5-diene ( _2,5 - _{norbornadiene} ), adamantine ( _C10H16 ), norbornene ( _C7H10 ), derivatives thereof, isomers thereof, or any combination thereof.

[0024] The dopant compound may be or include one or more metal dopants, one or more non-metal dopants, or a combination thereof. The dopant compound may be one or more chemical precursors used in a vapor deposition process such as CVD or ALD. The metal dopant may be or include one or more of tungsten, molybdenum, cobalt, nickel, vanadium, hafnium, zirconium, tantalum, or any combination thereof. Thus, the metal dopant may be or include one or more of a tungsten precursor, a molybdenum precursor, a cobalt precursor, a nickel precursor, a vanadium precursor, a hafnium precursor, a zirconium precursor, a tantalum precursor, or any combination thereof. Exemplary metal dopants may be or include tungsten hexafluoride, tungsten hexacarbonyl, molybdenum pentachloride, cyclopentadienyl dicarbonyl cobalt, dicobalt hexacarbonyl butylacetylene (CCTBA), bis(cyclopentadienyl)cobalt, bis(methylcyclopentadienyl)nickel, vanadium pentachloride, hafnium tetrachloride, tetrakis(dimethylamino)hafnium, tetrakis(diethylamino)hafnium, zirconium tetrachloride, bis(cyclopentadienyl)zirconium dihydride, tetrakis(dimethylamino)zirconium, tetrakis(diethylamino)zirconium, tantalum pentachloride, tantalum pentafluoride, pentakis(dimethylamino)tantalum, pentakis(diethylamino)tantalum, pentakis(ethylmethylamino)tantalum, adducts thereof, derivatives thereof, or any combination thereof. The non-metallic dopant may be or include one or more of boron, silicon, germanium, nitrogen, phosphorous, or any combination thereof. Thus, the non-metallic dopant may be or include one or more of a boron precursor, a silicon precursor, a germanium precursor, a nitrogen precursor, a phosphorous precursor, or any combination thereof. Exemplary non-metallic dopants may be or include disilane, diborane, triethylborane, silane, disilane, trisilane, germane, ammonia, hydrazine, phosphine, adducts thereof, or any combination thereof.

[0025] The substrate and/or the processing space can be heated and maintained at a separate temperature during the deposition process. The substrate and/or the processing space can be heated to a temperature of about 50°C, about 25°C, about 10°C, about 5°C, about 0°C, about 5°C, or about 10°C to about 15°C, about 20°C, about 23°C, about 30°C, about 50°C, about 100°C, about 150°C, about 200°C, about 300°C, about 400°C, about 500°C, or about 600°C. For example, the substrate and/or processing space may be heated to a temperature of about 50°C to about 600°C, about 50°C to about 450°C, about 50°C to about 350°C, about 50°C to about 200°C, about 50°C to about 100°C, about 50°C to about 50°C, about 50°C to about 0°C, about 0°C to about 600°C, about 0°C to about 450°C, about 0°C to about 350°C, about 0°C to about 200°C, about 0°C to about 120°C, about 0°C to about 100°C, about 0°C to about 80°C, about 0°C to about 50°C, about 0°C to about 25°C, about 10°C to about 600°C, about 10°C to about 450°C, about 10°C to about 350°C, about 10°C to about 200°C, about 10°C to about 100°C, or about 10°C to about 50°C.

[0026] The process space of the processing chamber is maintained at a subatmospheric pressure during the deposition process. The process space of the processing chamber is maintained at a pressure of about 0.1 mTorr, about 0.5 mTorr, about 1 mTorr, about 5 mTorr, about 10 mTorr, about 50 mTorr, or about 80 mTorr to about 100 mTorr, about 250 mTorr, about 500 mTorr, about 1 Torr, about 5 Torr, about 10 Torr, about 20 Torr, about 50 Torr, or about 100 Torr. For example, the processing space of the processing chamber may be from about 0.1 mTorr to about 10 Torr, from about 0.1 mTorr to about 5 Torr, from about 0.1 mTorr to about 1 Torr, from about 0.1 mTorr to about 500 mTorr, from about 0.1 mTorr to about 100 mTorr, from about 0.1 mTorr to about 10 mTorr, from about 1 mTorr to about 10 Torr, from about 1 mTorr to about 5 Torr, from about 1 mTorr to about 1 Torr, about 1 mTorr to about 500 mTorr, about 1 mTorr to about 100 mTorr, about 1 mTorr to about 10 mTorr, about 5 mTorr to about 10 Torr, about 5 mTorr to about 5 Torr, about 5 mTorr to about 1 Torr, about 5 mTorr to about 500 mTorr, about 5 mTorr to about 100 mTorr, or about 5 mTorr to about 10 mTorr.

[0027] The deposition gas may further include one or more dilution gases, carrier gases, and/or purge gases, such as, for example, helium, argon, xenon, neon, nitrogen ( _N2 ), hydrogen ( _H2 ), or any combination thereof. The deposition gas may further include an etchant gas, such as chlorine ( _Cl2 ), carbon tetrafluoride ( _CF4 ), and/or nitrogen trifluoride ( _NF3 ), to improve film quality. The plasma (e.g., a capacitively coupled plasma) may be formed from either the top and bottom electrodes or the side electrodes. These electrodes may be formed from a single powered electrode, from dual powered electrodes, or from more electrodes with multiple frequencies (such as, but not limited to, about 350 KHz, about 2 MHz, about 13.56 MHz, about 27 MHz, about 40 MHz, about 60 MHz, and about 100 MHz) and are used alternatively or simultaneously in a CVD system with any or all of the reactant gases listed herein to deposit thin films of diamond-like carbon used as hard masks and/or etch stops, or smooth carbon films required for any other application. The high etch selectivity of the doped diamond-like carbon film is achieved by having a higher density and modulus than existing produced films. Without being bound by theory, it is believed that the improved density and modulus result from an increased content of sp ³ hybridized carbon atoms in the doped diamond-like carbon film, which may be achieved by combining low pressure with plasma power.

[0028] In one or more embodiments, the doped diamond-like carbon film is deposited in a process chamber having a substrate pedestal maintained at about 10° C., a pressure maintained at about 2 mTorr, and a plasma generated at the substrate level by applying a bias of about 2,500 Watts (about 13.56 MHz) to the electrostatic chuck. In other embodiments, an additional RF power of about 1,000 Watts at about 2 MHz is also supplied to the electrostatic chuck to generate a dual bias plasma at the substrate level.

[0029] In one or more embodiments, hydrogen radicals are provided through the RPS, which leads to selective etching of sp ² hybridized carbon atoms, which in turn further increases the fraction of sp ³ hybridized carbon atoms in the film, thereby further increasing the etch selectivity. The doped diamond-like carbon film may have a concentration or percentage of sp 3 hybridized carbon atoms (e.g., sp 3 hybridized carbon atom content) that is at least 40 atomic percent (at%), about 45 at%, about 50 at%, about 55 at%, or about 58 at% to about 60 at%, about 65 at%, about 70 at%, about 75 at%, about 80 at%, about 85 at%, about 88 at%, about 90 at%, about 92 at%, or about 95 at%, based on the total amount of carbon atoms ⁱⁿ the ^doped diamond-like carbon film. For example, the doped diamond-like carbon film may have a doped carbon content of at least 40 at% to about 95 at%, about 45 at% to about 95 at%, about 50 at% to about 95 at%, about 50 at% to about 90 at%, about 50 at% to about 85 at%, about 50 at% to about 80 at%, about 50 at% to about 75 at%, about 50 at% to about 70 at%, about 50 at% to about 6 at%, based on the total amount of carbon atoms in the doped diamond-like carbon film. The concentration or percentage of sp3 hybridized carbon atoms may be 5 at%, about 65 at% to about 95 at%, about 65 at% to about 90 at%, about 65 at% to about 85 at%, about 65 at% to about 80 at%, about 65 at% to about 75 at%, about 65 at% to about 70 at%, about 65 at% to about 68 at%, about 75 at% to about 95 at%, about 75 at% to about 90 at%, about 75 at% to about 85 at%, about 75 at% to about 80 at%, or about ⁷⁵ at% to about 78 at%.

[0030] The doped diamond-like carbon film may have a dopant concentration or percentage of about 0.01 at%, about 0.05 at%, about 0.1 at%, about 0.3 at%, about 0.5 at%, about 0.8 at%, about 1 at%, about 1.2 at%, about 1.5 at%, about 1.8 at%, about 2 at%, about 2.5 at%, or about 2.8 at% to about 3 at%, about 3.5 at%, about 4 at%, about 5 at%, about 6 at%, about 7 at%, about 8 at%, about 9 at%, about 10 at%, about 12 at%, about 15 at%, about 18 at%, about 20 at%, about 25 at%, about 30 at%, or more, based on the total amount of atoms in the doped diamond-like carbon film. For example, the doped diamond-like carbon film may have a doping ratio of about 0.01 at% to about 25 at%, about 0.1 at% to about 25 at%, about 0.5 at% to about 25 at%, about 1 at% to about 25 at%, about 2 at% to about 25 at%, about 3 at% to about 25 at%, about 5 at% to about 25 at%, about 7 at% to about 25 at%, about 10 at% to about 25 at%, about 12 at% to about 25 at%, about 15 at% to about 25 at%, about 18 at% to about 25 at%, based on the total amount of atoms in the doped diamond-like carbon film. t%, about 20 at% to about 25 at%, about 0.1 at% to about 20 at%, about 0.5 at% to about 20 at%, about 1 at% to about 20 at%, about 2 at% to about 20 at%, about 3 at% to about 20 at%, about 5 at% to about 20 at%, about 7 at% to about 20 at%, about 10 at% to about 20 at%, about 12 at% to about 20 at%, about 15 at% to about 20 at%, about 18 at% to about 20 at%, about 0.1 at% to about 18 at%, about 0.5 at% to about 18 at%, about 1 at% to about 18 at%, about 2 at% to about 18 at%, about 3 at% to about 18 at%, about 5 at% to about 18 at%, about 7 at% to about 18 at%, about 10 at% to about 18 at%, about 12 at% to about 18 at%, about 15 at% to about 18 at%, about 0.1 at% to about 15 at%, about 0.5a t% to about 15 at%, about 1 at% to about 15 at%, about 2 at% to about 15 at%, about 3 at% to about 15 at%, about 5 at% to about 15 at%, about 7 at% to about 15 at%, about 10 at% to about 15 at%, about 12 at% to about 15 at%, about 0.01 The dopant concentration or ratio may be from about at% to about 10 at%, from about 0.1 at% to about 10 at%, from about 0.5 at% to about 10 at%, from about 1 at% to about 10 at%, from about 2 at% to about 10 at%, from about 3 at% to about 10 at%, from about 4 at% to about 10 at%, from about 5 at% to about 10 at%, from about 7 at% to about 10 at%, from about 0.01 at% to about 5 at%, from about 0.1 at% to about 5 at%, from about 0.5 at% to about 5 at%, from about 1 at% to about 5 at%, from about 2 at% to about 5 at%, or from about 3 at% to about 5 at%.

[0031] The doped diamond-like carbon film has a melting point of greater than 2 g/cc, e.g., about 2.1 g/cc, about 2.2 g/cc, about 2.3 g/cc, about 2.4 g/cc, about 2.5 g/cc, about 2.6 g/cc, about 2.7 g/cc, about 2.8 g/cc, about 2.9 g/cc, or about 3 g/cc to about 3.1 g/cc, about 3.2 g/cc, about 3. .4 g/cc, about 3.5 g/cc, about 3.6 g/cc, about 3.8 g/cc, about 4 g/cc, about 4.5 g/cc, about 5 g/cc, about 5.5 g/cc, about 6 g/cc, about 6.5 g/cc, about 7 g/cc, about 8 g/cc, about 9 g/cc, about 10 g/cc, about 11 g/cc, about 12 g/cc, or more. For example, the doped diamond-like carbon film may have a viscosity of from greater than 2 g/cc to about 12 g/cc, from greater than 2 g/cc to about 10 g/cc, from greater than 2 g/cc to about 8 g/cc, from greater than 2 g/cc to about 7 g/cc, from greater than 2 g/cc to about 5 g/cc, from greater than 2 g/cc to about 4 g/cc, from greater than 2 g/cc to about 3 g/cc, from about 2.5 g/cc or more to about 12 g/cc, from about 2.5 g/cc or more to about 10 g/cc, from about 2.5 g/cc or more to about 8 g/cc, from about 2.5 g/cc or more ~7 g/cc, approximately 2.5 g/cc or more ~ approximately 5 g/cc, approximately 2.5 g/cc or more ~ approximately 4 g/cc, approximately 2.5 g/cc or more ~ approximately 3 g/cc, approximately 3 g/cc or more ~ approximately 12 g/cc, approximately 3 g/cc or more ~ approximately 10 g/cc c, about 3 g/cc or more to about 8 g/cc, about 3 g/cc or more to about 7 g/cc, about 3 g/cc or more to about 5 g/cc, about 3 g/cc or more to about 4 g/cc, or about 3 g/cc or more to about 3.5 g/cc.

[0032] The doped diamond-like carbon film may have a thickness of about 5 Å, about 10 Å, about 50 Å, about 100 Å, about 150 Å, about 200 Å, or about 300 Å to about 400 Å, about 500 Å, about 800 Å, about 1,000 Å, about 2,000 Å, about 3,000 Å, about 5,000 Å, about 8,000 Å, about 10,000 Å, about 15,000 Å, about 20,000 Å, or more. For example, the doped diamond-like carbon film may have a thickness of about 5 Å to about 20,000 Å, about 5 Å to about 10,000 Å, about 5 Å to about 5,000 Å, about 5 Å to about 3,000 Å, about 5 Å to about 2,000 Å, about 5 Å to about 1,000 Å, about 5 Å to about 500 Å, about 5 Å to about 200 Å, about 5 Å to about 100 Å, about 5 Å to about 50 Å, about 300 Å to about 20,000 Å, about 300 Å to about 10,000 Å, about 00 Å to about 5,000 Å, about 300 Å to about 3,000 Å, about 300 It may have a thickness of about 2,000 Å, about 300 Å to about 1,000 Å, about 300 Å to about 500 Å, about 300 Å to about 200 Å, about 300 Å to about 100 Å, about 300 Å to about 50 Å, about 1,000 Å to about 20,000 Å, about 1,000 Å to about 10,000 Å, about 1,000 Å to about 5,000 Å, about 1,000 Å to about 3,000 Å, about 1,000 Å to about 2,000 Å, about 2,000 Å to about 20,000 Å, or about 2,000 Å to about 3,000 Å.

[0033] The doped diamond-like carbon film may have a refractive index or n value (n at 633 nm) greater than 2, e.g., about 2.1, about 2.2, about 2.3, about 2.4 or about 2.5 to about 2.6, about 2.7, about 2.8, about 2.9, or about 3. For example, the doped diamond-like carbon film may have a refractive index or n value (n at 633 nm) greater than 2 to about 3, greater than 2 to about 2.8, greater than 2 to about 2.5, greater than 2 to about 2.3, about 2.1 to about 3, about 2.1 to about 2.8, about 2.1 to about 2.5, about 2.1 to about 2.3, about 2.3 to about 3, about 2.3 to about 2.8, or about 2.3 to about 2.5.

[0034] The doped diamond-like carbon film may have an extinction coefficient or k value (k at 633 nm) greater than 0.1, e.g., about 0.15, about 0.2, about 0.25, or about 0.3, individually. For example, the doped diamond-like carbon film may have an extinction coefficient or k value (k at 633 nm) of greater than 0.1 to about 0.3, greater than 0.1 to about 0.25, greater than 0.1 to about 0.2, greater than 0.1 to about 0.15, about 0.2 to about 0.3, or about 0.2 to about 0.25.

[0035] Doped diamond-like carbon films may have a stress of less than -250 MPa, less than -275 MPa, about -300 MPa or less, about -350 MPa or less, about -400 MPa or less, about -450 MPa or less, about -500 MPa or less, about -550 MPa or less, about -600 MPa or less. For example, the doped diamond-like carbon film may have a viscosity of about -600 MPa to about -300 MPa, about -600 MPa to about -350 MPa, about -600 MPa to about -400 MPa, about -600 MPa to about -450 MPa, about -600 MPa to about -500 MPa, about -600 MPa to about -550 MPa, about -550 MPa to about -300 MPa, about -550 MPa to about 3-50 MPa, about -550 MPa to about -400 MPa, about -550 MPa to about -450 MPa, about -550 MPa to about -500 MPa, about -500 MPa to about -300 MPa, about -500 MPa to about - The stress may be about -350 MPa, about -500 MPa to about -400 MPa, or about -500 MPa to about -450 MPa.

[0036] The doped diamond-like carbon film may have an elastic modulus of greater than 150 GPa, e.g., about 175 GPa, about 200 GPa, or about 250 GPa to about 275 GPa, about 300 GPa, about 325 GPa, about 350 GPa, about 375 GPa, or about 400 GPa. For example, the doped diamond-like carbon film may have an elastic modulus of greater than 150 GPa to about 400 GPa, greater than 150 GPa to about 375 GPa, greater than 150 GPa to about 350 GPa, greater than 150 GPa to about 300 GPa, greater than 150 GPa to about 250 GPa, about 175 GPa to about 400 GPa, about 175 GPa to about 375 GPa, about It has an elastic modulus of 75 GPa to about 350 GPa, about 175 GPa to about 300 GPa, about 175 GPa to about 250 GPa, about 200 GPa to about 400 GPa, about 200 GPa to about 375 GPa, about 200 GPa to about 350 GPa, about 200 GPa to about 300 GPa, or about 200 GPa to about 250 GPa.

[0037] In some embodiments, the doped diamond-like carbon film is an underlayer for extreme ultraviolet ("EUV") lithography processing. In some embodiments, the doped diamond-like carbon film is an underlayer for EUV lithography processing and has a content of ^sp3 hybridized carbon atoms of about 40% to about 90%, based on the total amount of carbon atoms in the film, a density of greater than 2 g/cc to about 12 g/cc, and an elastic modulus of about 150 GPa to about 400 GPa.

1A shows a schematic diagram of a substrate processing system 132 that may be used to perform deposition of doped diamond-like carbon films 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 side wall 101, and a bottom wall 122 that define a processing space 126. A substrate support assembly 146 is provided within the processing space 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 may typically be fabricated from aluminum, ceramic, and other suitable materials. The electrostatic chuck 150 may be moved vertically within the processing chamber 100 using a displacement mechanism (not shown).

[0039] The vacuum pump 102 is connected 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 evacuates post-processing gases and processing by-products from the processing chamber 100.

[0040] The substrate processing system 132 may further include additional devices for controlling the chamber pressure, such as valves (such as throttle valves or isolation valves), positioned between the processing chamber 100 and the vacuum pump 102 to control the chamber pressure.

[0041] A gas distribution assembly 120 having a plurality of apertures 128 is disposed 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 processing gases (e.g., deposition gas, dilution gas, carrier gas, purge gas) into the processing chamber 100. The apertures 128 may have different sizes, quantities, distribution patterns, shapes, designs, and diameters to facilitate the flow of various processing gases for different processing requirements. The gas distribution assembly 120 is connected to a gas panel 130, which allows the supply of various gases to the processing space 126 during processing. A plasma is formed from the processing gas mixture exiting the gas distribution assembly 120 to enhance the pyrolysis of the processing gases resulting in the deposition of material on the surface 191 of the substrate 190.

[0042] The gas distribution assembly 120 and the electrostatic chuck 150 may form a spaced apart electrode pair within the process space 126. To facilitate the generation of a 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 a matching network 138 (which is optional). Alternatively, the RF power sources 140 and the matching network 138 may be coupled to the gas distribution assembly 120, to the electrostatic chuck 150, or to both the gas distribution assembly 120 and the electrostatic chuck 150, or may be coupled to an antenna (not shown) located outside the process chamber 100. In one or more embodiments, the RF power sources 140 may generate power at a frequency of about 350 KHz, about 2 MHz, about 13.56 MHz, about 27 MHz, about 40 MHz, about 60 MHz, or about 100 MHz. In some embodiments, the RF power source 140 can provide a power of about 100 watts to about 3,000 watts at a frequency of about 50 kHz to about 13.6 MHz. In other examples, the RF power source 140 can provide a power of about 500 watts to about 1,800 watts at a frequency of about 50 kHz to about 13.6 MHz.

[0043] The controller 110 includes a central processing unit (CPU) 112, memory 116, and support circuits 114, which are utilized to control the processing sequence and regulate the 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, for example, in random access memory, read-only memory, floppy or hard disk drives, or other forms of digital storage. The support circuits 114 are conventionally connected to the CPU 112 and may include cache, clock circuits, 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 through a number of signal cables, collectively referred to as signal buses 118, some of which are shown in FIG. 1A.

[0044] FIG. 1B illustrates 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 from the gas panel 130 through the sidewall 101 across the surface 191 of the substrate 190. In addition, the gas distribution assembly 120 shown in FIG. 1A is replaced with an electrode 182. The electrode 182 can be configured as a secondary charge generating device. In one or more embodiments, the electrode 182 is a silicon-containing electrode.

[0045] FIG. 2 shows a schematic cross-sectional view of a substrate support assembly 146 used in the processing system of FIGS. 1A and 1B that may be used in practicing embodiments described herein. Referring to FIG. 2, the electrostatic chuck 150 may include a heater element 170 adapted to control the temperature of a substrate 190 supported on a top 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 resistively heated by applying a current from a heater power supply 106 to the heater element 170. The heater power supply 106 may be coupled through an RF filter 216. The RF filter 216 may be used to protect the heater power supply 106 from RF energy. The heater element 170 may be made of a nickel-chromium wire enclosed in a sheath tube of a nickel-iron-chromium alloy (e.g., INCOLOY®). The current supplied by the heater power supply 106 is regulated by the controller 110 to control the heat generated by the heater element 170 and thus maintain the substrate 190 and electrostatic chuck 150 at a substantially constant temperature during film deposition. The current supplied can be adjusted to selectively control the temperature of the electrostatic chuck 150 from about 50° C. to about 600° C.

[0046] Referring to FIG. 1, in a conventional manner, 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 the controller 110 to control the power supplied to the heater element 170 to maintain the substrate at a desired temperature.

[0047] 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 and, when energized, electrostatically clamps the substrate 190 to the upper surface 192 of the electrostatic chuck 150.

[0048] The chucking electrode 210 may be configured as a monopolar or bipolar electrode, or may have another suitable configuration. The chucking electrode 210 may be coupled through an RF filter 214 to a chucking power supply 212, which provides direct current (DC) power to electrostatically clamp the substrate 190 to the upper surface 192 of the electrostatic chuck 150. The RF filter 214 prevents RF power utilized to form the plasma in the processing chamber 100 from damaging electrical equipment or causing electrical disturbances outside the chamber. The electrostatic chuck 150 may be fabricated from a ceramic material, such as aluminum nitride or aluminum oxide (e.g., alumina). Alternatively, the electrostatic chuck 150 may be fabricated from a polymer, such as polyimide, polyetheretherketone (PEEK), polyaryletherketone (PAEK), etc.

[0049] A power application system 220 is coupled to the substrate support assembly 146. The power application system 220 may include a heater power supply 106, a chucking power supply 212, a first radio frequency (RF) power supply 230, and a second RF power supply 240. The power application system 220 may 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 further 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.

[0050] As described above, the electrostatic chuck 150 includes, in one aspect, a chucking electrode 210 that functions to chuck the substrate 190 and may also function as a first RF electrode. The electrostatic chuck 150 may also include a second RF electrode 260, which, in conjunction with the chucking electrode 210, may apply RF power to condition the plasma. The first RF power source 230 may be coupled to the second RF electrode 260, while the 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 for each of the first RF power source 230 and the second RF power source 240. The second RF electrode 260 may be a solid metal plate of a conductive material as shown. Alternatively, the second RF electrode 260 may be a mesh of a conductive material.

[0051] 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 one or more embodiments, one or both of the first RF power source 230 and the second RF power source 240 may individually generate power at a frequency between about 350 KHz and about 100 MHz (e.g., 350 KHz, 2 MHz, 13.56 MHz, 27 MHz, 40 MHz, 60 MHz, or 100 MHz). In one or more embodiments, the first RF power source 230 may generate power at a frequency of 13.56 MHz and the second RF power source 240 may generate power at a frequency of 2 MHz, or vice versa. The RF power from one or both of the first RF power source 230 and the second RF power source 240 may be varied to tune the plasma. For example, the sensor device 250 may be used to monitor RF energy from one or both of the first RF power source 230 and the second RF power source 240. Data from the sensor device 250 may be transmitted to the controller 110, which may be utilized to modify the power applied by the first RF power source 230 and the second RF power source 240.

[0052] In one or more embodiments, the electrostatic chuck 150 may separate the chucking electrode 210 and the RF electrode from one another and may apply a first RF bias to the RF electrode 260 and a second RF bias to the chucking electrode 210. In one or more examples, the first RF bias is provided at a frequency of about 350 KHz to about 100 MHz and at a power of about 10 Watts to about 3,000 Watts, and the second RF bias is provided at a frequency of about 350 KHz to about 100 MHz and at a power of about 10 Watts to about 3,000 Watts. In other examples, the first RF bias is provided at a frequency of about 13.56 MHz and at a power of about 2,500 Watts to about 3,000 Watts, and the second RF bias is provided at a frequency of about 2 MHz and at a power of about 800 Watts to about 1,200 Watts.

[0053] In one or more embodiments, a deposition gas including one or more hydrocarbon compounds and one or more dopant compounds may be flowed or introduced into a processing space of a processing chamber, such as a PE-CVD chamber. The hydrocarbon compounds and the dopant compounds may be flowed or introduced into the processing space separately. In some examples, one or more substrates are placed on an electrostatic chuck in the processing chamber. The electrostatic chuck may have a separate chucking electrode and an RF electrode. A plasma may be ignited or generated at or near the substrate (e.g., at the substrate level) by applying a first RF bias to the RF electrode and a second RF bias to the chucking electrode. A doped diamond-like carbon film is deposited or formed on the substrate. In some embodiments, a patterned photoresist layer may be deposited or formed on the doped diamond-like carbon film, the doped diamond-like carbon film is etched or formed in a pattern corresponding to the patterned photoresist layer, and the pattern is etched or formed in the substrate.

[0054] In general, the following exemplary deposition process parameters may be used to form doped diamond-like carbon films: The substrate temperature may range from about 50° C. to about 350° C. (e.g., from about about 10° C. to about 100° C., or from about 10° C. to about 50° C.). The chamber pressure may range from about 0.5 mTorr to about 10 Torr (e.g., from about 2 mTorr to about 50 mTorr, or from about 2 mTorr to about 10 mTorr). The flow rate of the hydrocarbon compound may range from about 10 sccm to about 1,000 sccm (e.g., from about 100 sccm to about 200 sccm, or from about 150 sccm to about 200 sccm). The flow rate of the dopant compound can be from about 1 sccm to about 1000 sccm (e.g., from about 10 sccm to about 150 sccm, or from about 20 sccm to about 100 sccm). The flow rate of the dilution gas or purge gas can be from about 50 sccm to about 50,000 sccm (e.g., from about 50 sccm to about 500 sccm, or from about 50 sccm to about 100 sccm).

[0055] The doped diamond-like carbon film may be deposited to a thickness of about 5 Å to about 20,000 Å (e.g., about 300 Å to about 5,000 Å, about 2,000 Å to about 3,000 Å, or about 5 Å to about 200 Å). The above process parameters shown in Table 1 provide example process parameters for a 300 mm substrate in a deposition chamber available from Applied Materials, Inc. of Santa Clara, Calif.

[0056] The doped diamond-like carbon film may have a refractive index or n value (n at 633 nm) greater than 2.0, e.g., from about 2.1 to about 3.0, 2.3, etc. The doped diamond-like carbon film may have an extinction coefficient or k value (K at 633 nm) greater than 0.1, e.g., from about 0.2 to about 0.3, 0.25, etc. The doped diamond-like carbon film may have a stress of less than about -100 MPa (e.g., from about -1,000 MPa to about -100 MPa, from about -600 MPa to about -300 MPa, from about -600 MPa to about -500 MPa, about -550 MPa, etc.). The doped diamond-like carbon film may have a density greater than 2 g/cc (e.g., about 2.5 g/cc or greater, about 2.8 g/cc or greater, about 3 g/cc to about 12 g/cc, etc.) The doped diamond-like carbon film may have an elastic modulus greater than 150 GPa (e.g., about 200 GPa to about 400 GPa).

[0057] FIG. 3 shows a flow diagram of a method 300 for forming a doped diamond-like carbon film on a film stack disposed on a substrate according to one embodiment of the present disclosure. The doped diamond-like carbon film formed on the film stack can be used, for example, as a hard mask for forming a step-like structure in the film stack. FIGS. 4A and 4B are schematic cross-sectional views showing a sequence for forming a doped diamond-like carbon film on a film stack disposed on a substrate by the method 300. Although the method 300 is described below in the context of a hard mask layer that can be formed on a film stack used to fabricate a step-like structure in a film stack for a three-dimensional semiconductor device, the method 300 can also be advantageously used in other device manufacturing applications. It should further be understood that the steps shown in FIG. 3 can be performed simultaneously and/or in a different order than that shown in FIG. 3.

[0058] The method 300 begins in step 310 by positioning a substrate (such as the substrate 402 shown in FIG. 4A) in a process chamber (such as the process chamber 100 shown in FIG. 1A or FIG. 1B). The substrate 402 may be the substrate 190 shown in FIGS. 1A, 1B, and 2. The substrate 402 may be positioned on an electrostatic chuck (e.g., the upper surface 192 of the electrostatic chuck 150). The substrate 402 may be a silicon-based material, or any suitable insulating or conductive material as desired, with a film stack 404 disposed thereon, which may be utilized to form a structure 400 (e.g., a stepped structure) in the film stack 404.

[0059] As shown in the embodiment depicted in FIG. 4A, the substrate 402 may have a substantially planar surface, a non-planar surface, or a substantially planar surface with structures formed thereon. A film stack 404 is formed on the substrate 402. In one or more embodiments, the film stack 404 may be utilized to form gate structures, contact structures, or interconnect structures in front-end or back-end processing. The method 300 may be performed on the film stack 404 to form stepped structures used in memory structures (such as NAND structures) in the film stack 404. In one or more embodiments, the substrate 402 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, patterned or unpatterned substrate silicon-on-insulator (SOI), carbon doped silicon oxide, silicon nitride, doped silicon, germanium, gallium arsenide, glass, sapphire, etc. The substrate 402 may have various dimensions, for example, 200 mm, 300 mm, and 450 mm, or other diameters, and may be a rectangular or square panel. 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 the substrate 402 utilizes an SOI structure, the substrate 402 may include a buried dielectric layer disposed on a silicon crystalline substrate. In one or more embodiments described herein, the substrate 402 may be a crystalline silicon substrate.

[0060] In one or more embodiments, the film stack 404 disposed on the substrate 402 may have multiple vertically stacked layers. The film stack 404 may include 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 repeated in the film stack 404. These pairs include alternating first layers (shown as _408a1 , _408a2 , _408a3 , ..., _408an ) and second layers (shown as _408b1 , _408b2 , _408b3 , ..., _408bn ), and are repeatedly formed until a target number of pairs of first and second layers is reached.

[0061] The film stack 404 may be part of a semiconductor chip, such as a three-dimensional memory chip. It should be noted that although three repeating layers of a first layer (shown as _408a1 , _408a2 , _408a3 , ..., 408a _n ) and a second layer (shown as _408b1 , _408b2 , _408b3 , ..., 408b _n ) are shown in Figures 4A-B, any desired number of repeating pairs of first and second layers may be utilized as desired.

[0062] In one or more embodiments, the film stack 404 may be utilized to form multiple gate structures for a three-dimensional memory chip. The first layers _408a1 , _408a2 , _408a3 ,..., _408an formed in the film stack 404 may be first dielectric layers, and the second layers _408b1 , _408b2 , _408b3 ,..., _408bn may be second dielectric layers. The first layers _408a1 , _408a2 , _408a3 ,..., _408an and the second layers _408b1 , _408b2 , _408b3 ,... , 408b _n may include, among others, 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 one or more embodiments, the dielectric layer may be a high-k material having a dielectric constant greater than 4. Suitable examples of high-k materials include hafnium oxide, zirconium oxide, titanium oxide, hafnium silicon oxide or hafnium silicate, hafnium aluminum oxide or hafnium aluminate, zirconium silicon oxide or zirconium silicate, tantalum oxide, aluminum oxide, aluminum doped hafnium dioxide, bismuth strontium titanium (BST), and platinum zirconium titanium (PZT), dopants thereof, or any combination thereof.

[0063] In one or more examples, the first layers _408a1 , _408a2 , _408a3 ,..., _408an are silicon oxide layers and the second layers _408b1 , 408b2, _{408b3,..., 408bn are silicon nitride layers or polysilicon layers disposed on the first layers 408a1, 408a2 , 408a3} ,..., 408an. In one or more embodiments, the first layers _408a1 , _408a2 , _408a3 ,..., _408an are silicon oxide layers and the second layers 408b1, 408b2, 408b3,..., 408bn are silicon nitride layers or polysilicon layers disposed on the first layers _408a1 , _408a2 , _408a3 ,..., 408an. , 408a _n may be controlled in thickness from about 50 Å to about 1,000 Å (e.g., about 500 Å) and the thickness of each of the second layers 408b ₁ , 408b ₂ , 408b ₃ , ..., 408b _n may be controlled in thickness from about 50 Å to about 1,000 Å (e.g., about 500 Å). The film stack 404 may have a total thickness from about 100 Å to about 2,000 Å. In one or more embodiments, the total thickness of the film stack 404 is from about 3 microns to about 10 microns, and will vary as technology advances.

[0064] It should be noted that a doped diamond-like carbon film may be formed on any surface or any portion of the substrate 402, regardless of whether or not a film stack 404 is present on the substrate 402.

[0065] In step 320, a chucking voltage is applied to the electrostatic chuck to clamp or place the substrate 402 on the electrostatic chuck. In one or more embodiments in which the substrate 402 is positioned on the top surface 192 of the electrostatic chuck 150, the top surface 192 supports and clamps the substrate 402 during processing. The electrostatic chuck 150 seals the substrate 402 to the top surface 192 to prevent backside deposition. An electrical bias is provided to the substrate 402 via the chucking electrode 210. The chucking electrode 210 may be in electrical communication with a chucking power supply 212 that provides a bias voltage to the chucking electrode 210. In one or more embodiments, the chucking voltage is from about 10 volts to about 3,000 volts, from about 100 volts to about 2,000 volts, or from about 200 volts to about 1,000 volts.

[0066] In step 320, several process parameters may be adjusted for processing. In one or more embodiments suitable for processing a 300 mm substrate, the process pressure in the process space may be maintained between about 0.1 mTorr and about 10 Torr (e.g., between about 2 mTorr and about 50 mTorr, or between about 5 mTorr and about 20 mTorr). In some embodiments suitable for processing a 300 mm substrate, the process temperature and/or substrate temperature may be maintained between about 50° C. and about 350° C. (e.g., between about 0° C. and about 50° C., or between about 10° C. and about 20° C.).

[0067] In one or more embodiments, a constant chucking voltage is applied to the substrate 402. In some embodiments, the chucking voltage may be pulsed to the electrostatic chuck 150. In other embodiments, a backside gas may be applied to the substrate 402 while the chucking voltage is applied to control the temperature of the substrate. The backside gas may include, but is not limited to, helium, argon, neon, nitrogen ( _N2 ), hydrogen ( _H2 ), or any combination thereof.

[0068] In step 330, a plasma is generated at the substrate, for example adjacent to the substrate or near the substrate level, by applying a first RF bias to the electrostatic chuck. The plasma generated at the substrate can be generated in a plasma region between the substrate and the electrostatic chuck. The first RF bias can be from about 10 watts to about 3,000 watts at a frequency of about 350 KHz to about 100 MHz (e.g., 350 KHz, about 2 MHz, about 13.56 MHz, about 27 MHz, about 40 MHz, about 60 MHz, or about 100 MHz). In one or more embodiments, the first RF bias is provided at a frequency of about 13.56 MHz and with a power of about 2,500 watts to about 3,000 watts. In one or more embodiments, the first RF bias is provided to the electrostatic chuck 150 via the second RF electrode 260. The second RF electrode 260 may be in electrical communication with the first RF power source 230, which provides a bias voltage to the second RF electrode 260. In one or more embodiments, the bias power is from about 10 watts to about 3,000 watts, from about 2,000 watts to about 3,000 watts, or from about 2,500 watts to about 3,000 watts. The first RF power source 230 may generate power at a frequency of from about 350 KHz to about 100 MHz (e.g., about 350 KHz, about 2 MHz, about 13.56 MHz, about 27 MHz, about 40 MHz, about 60 MHz, or about 100 MHz).

[0069] In one or more embodiments, step 330 further includes applying a second RF bias to the electrostatic chuck. The second RF bias can be from about 10 watts to about 3,000 watts at a frequency of about 350 KHz to about 100 MHz (e.g., about 350 KHz, about 2 MHz, about 13.56 MHz, about 27 MHz, about 40 MHz, about 60 MHz, or about 100 MHz). In some embodiments, the second RF bias is provided at a frequency of about 2 MHz and with a power of about 800 watts to about 1,200 watts. In other examples, the second RF bias is provided to the substrate 402 via the chucking electrode 210. The chucking electrode 210 can be in electrical communication with a second RF power source 240 that provides a bias voltage to the chucking electrode 210. In one or more embodiments, the bias power is between about 10 watts and about 3,000 watts, between about 500 watts and about 1,500 watts, or between about 800 watts and about 1,200 watts. The second RF power source 240 may generate power at a frequency between about 350 KHz and about 100 MHz (e.g., about 350 KHz, about 2 MHz, about 13.56 MHz, about 27 MHz, about 40 MHz, about 60 MHz, or about 100 MHz). In one or more embodiments, the chucking voltage provided during step 320 is maintained during step 330.

[0070] In some embodiments, during step 330, a first RF bias may be supplied to the substrate 402 via the chucking electrode 210 and a second RF bias may be supplied to the substrate 402 via the second RF electrode 260. In one or more embodiments, the first RF bias is about 2,500 Watts (about 13.56 MHz) and the second RF bias is about 1,000 Watts (about 2 MHz).

[0071] In step 340, deposition gas is flowed into the process space 126 to form a doped diamond-like carbon film on the film stack. The deposition gas may be flowed into the process space 126 from the gas panel 130, through the gas distribution assembly 120, or through the sidewall 101. The deposition gas includes one or more hydrocarbon compounds and one or more dopant compounds. The hydrocarbon compounds may be or include one, two, or more hydrocarbon compounds in any state of matter. Similarly, the dopant compounds may be or include one, two, or more hydrocarbon compounds in any state of matter. The hydrocarbons and/or dopant compounds may be either liquids or gases, although some advantages may be realized if any of the precursors are vapors at room temperature to simplify the hardware required to meter, control, and deliver the materials to the process space.

[0072] The deposition gas may further include an inert gas, a diluent gas, an etchant gas, or a combination thereof. In one or more embodiments, the chucking voltage provided during step 320 is maintained during step 340. In some embodiments, the process conditions established during step 320 and the plasma formed during step 330 are maintained during step 340.

[0073] In one or more embodiments, the hydrocarbon compound is a gaseous hydrocarbon or a liquid hydrocarbon. The hydrocarbon can be or include one or more alkanes, one or more alkenes, one or more alkynes, one or more aromatics, or any combination thereof. In some embodiments, the hydrocarbon compound is represented by the general formula _CxHy , where x has a range from 1 to 20 and _y has a range 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), _adamantine ( _C10H16 ), _norbornene ( _C7H10 ), or any combination thereof. In one or more embodiments, ethyne is utilized to form a more stable intermediate species that allows for enhanced surface mobility.

[0074] The hydrocarbon compound can be or include one or more alkanes (e.g., C _n H _2n+2 , where n is 1 to 20). Suitable hydrocarbon compounds include alkanes (e.g., methane (CH ₄ ), ethane (C ₂ H ₆ ), propane (C ₃ H ₈ ), butane (C ₄ H ₁₀ ) and its isomers isopentane, pentane (C ₅ H ₁₂ ), hexane (C ₆ H ₁₄ ) and its isomers isopentane and neopentane, hexane (C ₆ H ₁₄ ) and its isomers 2-methylpentane, 3-methylpentane, 2,3-dimethylbutane, and 2,2-dimethylbutane, or combinations thereof).

[0075] The hydrocarbon compound can be or include one or more alkenes (e.g., C _n H _2n , where n is 1 to 20). Suitable hydrocarbon compounds include, for example, alkenes such as ethylene, propylene (C ₃ H ₆ ), butylene and its isomers, pentene and its isomers, dienes such as butadiene, isoprene, pentadiene, hexadiene, or combinations thereof. Further suitable hydrocarbons include, for example, halogenated alkenes (e.g., monofluoroethylene, difluoroethylene, trifluoroethylene, tetrafluoroethylene, monochloroethylene, dichloroethylene, trichloroethylene, tetrachloroethylene, or any combination thereof).

[0076] The hydrocarbon compound can be or include one or more alkynes (e.g., C _n H _2n2 , where n is 1 to 20). Suitable hydrocarbons include, for example, alkynes (e.g., acetylene (C ₂ H ₄ ), propyne (C ₃ H ₄ ), butylene (C ₄ H ₈ ), vinyl acetylene, or combinations thereof).

[0077] The hydrocarbon compound may be or include one or more aromatic hydrocarbon compounds (e.g., benzene, styrene, toluene, xylene, ethylbenzene, acetophenone, methyl benzoate, phenyl acetate, phenol, cresol, furan, etc.), alpha-terpinene, cymene, 1,1,3,3-tetramethylbutylbenzene, t-butyl ether, t-butyl ethylene, methyl methacrylate, and t _- butyl furfuryl ether, compounds having the chemical formulas _C3H2 and _{C5H4 ,} halogenated aromatic compounds (including monofluorobenzene, difluorobenzene, tetrafluorobenzene, hexafluorobenzene, or any combination thereof).

[0078] Exemplary tungsten precursors may be or include tungsten hexafluoride, tungsten hexachloride, tungsten hexacarbonyl, bis(cyclopentadienyl)tungsten dihydride, bis(tertbutylimino)bis(dimethylamino)tungsten, or any combination thereof. Exemplary molybdenum precursors may be or include molybdenum pentachloride, molybdenum hexacarbonyl, bis(cyclopentadienyl)molybdenum dichloride, or any combination thereof. Exemplary cobalt precursors may be or include one or more of cobalt carbonyl compounds, cobalt amidinate compounds, cobaltocene compounds, cobalt dienyl compounds, complexes thereof, or any combination thereof. Exemplary cobalt precursors may be, or may include, one or more of cyclopentadienyl dicarbonyl cobalt (CpCo(CO) ₂ ), dicobalt hexacarbonyl butylacetylene (CCTBA), (cyclopentadienyl)(cyclohexadienyl)cobalt, (cyclobutadienyl)(cyclopentadienyl)cobalt, bis(cyclopentadienyl)cobalt, bis(methylcyclopentadienyl)cobalt, bis(ethylcyclopentadienyl)cobalt, cyclopentadienyl(1,3-hexadienyl)cobalt, (cyclopentadienyl)(5-methylcyclopentadienyl)cobalt, and bis(ethylene)(pentamethylcyclopentadienyl)cobalt, or any combination thereof.

[0079] Exemplary nickel precursors can be or include bis(cyclopentadienyl)nickel, bis(ethylcyclopentadienyl)nickel, bis(methylcyclopentadienyl)nickel, allyl(cyclopentadienyl)nickel, or any combination thereof. Exemplary vanadium precursors can be or include vanadium pentachloride, bis(cyclopentadienyl)vanadium, or any combination thereof. Exemplary zirconium precursors can be or include zirconium tetrachloride, bis(cyclopentadienyl)zirconium dihydride, tetrakis(dimethylamino)zirconium, tetrakis(diethylamino)zirconium, or any combination thereof.

[0080] The hafnium precursor may be or include one or more hafnium cyclopentadiene compounds, one or more hafnium amino compounds, one or more hafnium alkyl compounds, one or more hafnium alkoxy compounds, substitutes thereof, complexes thereof, addition compounds thereof, salts thereof, or any combination thereof. Exemplary hafnium precursors may be or _{include bis(methylcyclopentadiene)dimethylhafnium ((MeCp)2HfMe2 )} , bis(methylcyclopentadiene)methylmethoxyhafnium ((MeCp) _2Hf (OMe)(Me)), bis(cyclopentadiene)dimethylhafnium ((Cp) _2HfMe2 ), tetra(tert _- butoxy)hafnium, hafnium isopropoxide ((iPrO) _4Hf ), tetrakis(dimethylamino)hafnium (TDMAH), tetrakis(diethylamino)hafnium (TDEAH), tetrakis(ethylmethylamino)hafnium (TEMAH), isomers thereof, complexes thereof, adducts thereof, salts thereof, or any combination thereof.

[0081] Exemplary tantalum-containing compounds can be or include pentakis(ethylmethylamino)tantalum (PEMAT), pentakis(diethylamino)tantalum (PDEAT), pentakis(dimethylamino)tantalum (PDMAT), and any derivatives of PEMAT, PDEAT, and PDMAT. Exemplary tantalum-containing compounds also include tert-butyliminotris(diethylamino)tantalum (TBTDET), tert-butyliminotris(dimethylamino)tantalum (TBTDMT), bis(cyclopentadienyl)tantalum trihydride, bis(methylcyclopentadienyl)tantalum trihydride, and tantalum halides, TaX ₅ , where X is fluorine (F), bromine (Br), or chlorine (Cl), and/or derivatives thereof. Exemplary nitrogen-containing compounds include nitrogen gas, ammonia, hydrazine, methylhydrazine, dimethylhydrazine, t-butylhydrazine, phenylhydrazine, azoisobutane, ethyl azide, and derivatives thereof.

[0082] Exemplary silicon precursors can be or include silane, disilane, trisilane, tetrasilane, pentasilane, hexasilane, monochlorosilane, dichlorosilane, trichlorosilane, tetrachlorosilane, hexachlorosilane, substituted silanes, plasma derivatives thereof, or any combination thereof. Exemplary boron precursors can be or include diborane, triborane, tetraborane, triethylborane ( _Et3B ), dimethylaminoborane, or any combination thereof.

[0083] The nitrogen-containing compound may be or include one or more of pyridine compounds, aliphatic amines, amines, nitriles, and similar compounds. Exemplary nitrogen-containing compounds may be or include nitrogen gas, atomic nitrogen, ammonia, hydrazine, methylhydrazine, dimethylhydrazine, t-butylhydrazine, phenylhydrazine, azoisobutane, ethylazide, and derivatives thereof. Exemplary phosphorus precursors may be or include phosphine, triphenylphosphine, trimethylphosphine, triethylphosphine, or any combination thereof. Exemplary germanium precursors may be or include germane, tetramethylgermanium, triethylgermanium hydride, triphenylgermanium hydride, or any combination thereof.

[0084] In one or more embodiments, the deposition gas further comprises one or more dilution gases, one or more carrier gases, and/or one or more purge gases. Suitable dilution gases, carrier gases, and/or purge gases, such as helium (He), argon (Ar), xenon (Xe), hydrogen ( _H2 ), nitrogen ( _N2 ), ammonia ( _NH3 ), nitric oxide (NO), or any combination thereof, among others, may be co-flowed or supplied to the process space 126 with the deposition gas. Argon, helium, and/or nitrogen may be used to control the density and deposition rate of the doped diamond-like carbon film. In some cases, the addition of _N2 and/or _NH3 may be used to control the hydrogen ratio in the doped diamond-like carbon film, as described below. Alternatively, no dilution gas may be used during deposition.

[0085] In some embodiments, the deposition gas further comprises an etchant gas. Suitable etchant gases are or include chlorine ( _Cl2 ), fluorine ( _F2 ), hydrogen fluoride (HF), carbon tetrafluoride ( _CF4 ), nitrogen trifluoride ( _NF3 ), or combinations thereof. Without being bound by theory, it is believed that the etchant gas selectively etches ^sp2 hybridized carbon atoms from the film, thus increasing the fraction of ^sp3 hybridized carbon atoms in the film, thereby increasing the etch selectivity of the film.

[0086] In one or more embodiments, after the doped diamond-like carbon film 412 is formed on the substrate in step 340, the doped diamond-like carbon film 412 is exposed to hydrogen radicals. In some embodiments, the doped diamond-like carbon film is exposed to hydrogen radicals during the deposition process of step 340. In other embodiments, the hydrogen radicals are formed in the RPS and supplied to the process region. Without being bound by theory, it is believed that exposing the doped diamond-like carbon film to hydrogen radicals leads to selective etching of ^sp2 hybridized carbon atoms, thereby increasing the fraction of ^sp3 hybridized carbon atoms in the film, thereby enhancing etch selectivity.

[0087] In step 350, after the doped diamond-like carbon film 412 is formed on the substrate, the substrate is dechucked. During step 350, the chucking voltage is turned off. The reactive gases are also turned off and, optionally, purged from the processing chamber. In one or more embodiments, the RF power is reduced (e.g., about 200 watts) during step 350. Optionally, the controller 110 monitors the change in impedance to determine if the electrostatic charge has dissipated through the RF path to ground. Once the substrate is dechucked from the electrostatic chuck, residual gas is purged from the processing chamber. The processing chamber is pumped down and the substrate is lifted on lift pins and transported out of the chamber.

[0088] Figure 5 shows a flow diagram of a method 500 of using a doped diamond-like carbon film according to one or more embodiments described and illustrated herein. After the doped diamond-like carbon film 412 is formed on a substrate, it can be used as a patterning mask to form three-dimensional structures (such as staircase structures) in an etching process. The doped diamond-like carbon film 412 can be patterned using standard photoresist patterning techniques. In step 510, a patterned photoresist (not shown) can be formed on the doped diamond-like carbon film 412. In step 520, the doped diamond-like carbon film 412 can be etched with a pattern corresponding to the patterned photoresist layer, which is then etched into the substrate 530. In step 540, material can be deposited into the etched portion of the substrate 402. In step 550, the doped diamond-like carbon film 412 can be removed using a solution containing hydrogen peroxide and sulfuric acid. One exemplary solution that includes hydrogen peroxide and sulfuric acid is known as piranha solution or piranha etchant. The doped diamond-like carbon film 412 may also be removed using an etching chemistry that contains oxygen and a halogen (e.g., fluorine or chlorine) (e.g., _Cl2 / _O2 , _CF4 / _O2 , _Cl2 / _O2 / _CF4 ). The doped diamond-like carbon film 412 may also be removed by a chemical mechanical polishing (CMP) process.

Logical example:
[0089] The following non-limiting examples are provided to further illustrate the implementations described herein. However, these examples are not intended to be exhaustive or to limit the scope of the embodiments described herein. Some actual and predicted results are shown in Table II.

[0090] In one or more embodiments, the low stress high density boron doped diamond-like carbon films of the present disclosure are deposited using about 150 sccm acetylene, about 100 sccm helium, and 100 sccm diborane (diluted with 90 vol% _H2 ) as deposition gases. The substrate was at a temperature of about 10°C and the chamber pressure was maintained at about 5 mTorr while about 2,500 Watts of RF (13.56 MHz) power and about 1,000 Watts (2 MHz) were applied to the CVD reactor through the substrate pedestal (electrostatic chuck) with Ar and/or He as diluent gases.

[0091] The resulting boron doped diamond-like carbon films have a density greater than 2 g/cc, e.g., 2.5 g/cc to about 3 g/cc, or about 5 g/cc, a stress of -500 MPa or less, e.g. , -550 MPa or -600 MPa, and a K<0.15 at 633 nm. The boron doped diamond-like carbon films have a higher etch selectivity than currently available amorphous carbon films or other conventional undoped diamond-like carbon films.

[0092] In another embodiment, high density tungsten doped diamond-like carbon films of the present disclosure were produced by flowing about 150 sccm acetylene, about 100 sccm helium, and 20 sccm tungsten hexafluoride as deposition gases. The substrate was at a temperature of about 10° C. and the chamber pressure was maintained at about 5 mTorr while about 2,500 watts of RF (13.56 MHz) power and about 1,000 watts (2 MHz) were applied to the CVD reactor through the substrate pedestal (electrostatic chuck) with Ar and/or He as diluent gases.

[0093] The resulting tungsten doped diamond-like carbon films have a density greater than 3 g/cc, e.g., 3.5 g/cc to about 10 g/cc, or about 12 g/cc, a stress of -550 MPa or less, e.g. , -600 MPa or -650 MPa, and a K<0.15 at 633 nm. The tungsten doped diamond-like carbon films have a higher etch selectivity than currently available amorphous carbon films or other conventional undoped diamond-like carbon films.

Extreme Ultraviolet (EUV) Patterning Schemes [0094] When using metal-containing photoresists in extreme ultraviolet (EUV) patterning schemes, the choice of underlayer becomes important to prevent nanofailures (e.g., bridging and spacing defects) in semiconductor devices. The traditional underlayer for EUV patterning (lithography) schemes is a spin-on-carbon (SOC) material. However, during patterning, metals such as tin, for example, diffuse through the SOC material, leading to nanofailures in semiconductor devices. Such nanofailures act to degrade, degrade, and impede semiconductor performance.

[0095] On the other hand, the dense carbon films described herein have superior film qualities (e.g., improved hardness and density). Such hardness and density enable the dense carbon films to act as a much stronger barrier to metal intrusion and prevent (or at least reduce) micro defects than conventional SOC films. In one or more embodiments, a doped diamond-like carbon film is provided for use as an underlayer for extreme ultraviolet (EUV) lithography processing.

[0096] In one or more embodiments, the doped diamond-like carbon film used as an underlayer for EUV lithography processing may be any film described herein. The doped diamond-like carbon film may have an sp 3 hybridized carbon atom content of about 40% to about 90%, a density greater than 2 g/cc, for example about 2.5 g/cc to about 12 g/cc or about 3 g/cc to about 10 g/cc, and an elastic modulus of about 150 GPa to about 400 GPa, based on the total amount of carbon atoms in the ^doped diamond-like carbon film.

[0097] In some embodiments, doped diamond-like carbon films used as underlayers for EUV lithography processing have a density of 2.5 g/cc to 12 g/cc and an elastic modulus of about 180 GPa to about 200 GPa. The doped diamond-like carbon films have a density of about 3 g/cc and an elastic modulus of about 195 GPa. In other embodiments, the doped diamond-like carbon films have a stress of about -600 MPa, a refractive index of about 2.0 to about 3.0, and an extinction coefficient of about 0.2 and about 0.3.

[0098] Thus, methods and apparatus are provided for forming a hard mask layer that is or includes a doped diamond-like carbon film that can be used to form stepped structures for manufacturing three-dimensional stacks of semiconductor devices. By utilizing a doped diamond-like carbon film as a hard mask layer with the desired robust film properties and etch selectivity, improved dimensional and profile control of the resulting structures formed in the film stack can be obtained, enhancing the electrical performance of chip devices in applications for three-dimensional stacks of semiconductor devices.

[0099] Thus, some of the advantages of the present disclosure provide a process for depositing or forming a doped diamond-like carbon film on a substrate. Typical PE-CVD hardmask films have a very low percentage of hybrid sp ³ atoms and therefore low modulus and etch selectivity. Some of the embodiments described herein allow for the production of doped films with about 60% or more hybrid sp ³ atoms using low process pressures (less than 1 Torr) and bottom driven plasma, which provides improved etch selectivity compared to previously available hardmask films. In addition, some of the embodiments described herein are performed at low substrate temperatures, which allows for the deposition of other dielectric films at much lower temperatures than currently possible, opening up applications with low thermal budgets that could not previously be addressed by CVD. In addition, some of the embodiments described herein may be used as underlayers for EUV lithography processing.

[00100] The above is directed to embodiments of the present disclosure, however, other and further embodiments of the present disclosure may be devised without departing from the basic scope of the present disclosure, the scope of which is determined by the following claims. All documents described herein are incorporated by reference, including any priority documents and/or test procedures, to the extent not inconsistent with this text. As is apparent from the summary and specific embodiments set forth above, forms of the present disclosure have been illustrated and described, but various modifications may be made without departing from the spirit and scope of the present disclosure. Thus, it is not intended that the present disclosure be limited to the forms of the present disclosure as illustrated and described. Similarly, the term "comprising" is considered to be synonymous with the term "including" under US law. Similarly, whenever a composition, element, or group of elements is preceded by the transitional phrase "comprising," it is understood that the same composition or group of elements having the transitional phrase "consisting essentially of," "consisting of," "selected from the group of consisting of," or "is" prior to the recitation of the composition, one or more elements is also contemplated, and vice versa.

[00101] Certain embodiments and features are described using a set of upper numerical limits and a set of lower numerical limits. It should be recognized that ranges including combinations of any two values (e.g., any lower value with any upper value, any two lower values, and/or any two upper values) are envisioned unless otherwise indicated. Certain lower limits, upper limits, and ranges are set forth in one or more claims below.

Claims (20)

1. A method for processing a substrate, comprising:
flowing a deposition gas comprising a hydrocarbon compound and a dopant compound into a process space of a process chamber having a substrate disposed on an electrostatic chuck, the process space being maintained at a pressure between 0.5 mTorr and 10 Torr; generating a plasma at the substrate by applying a first RF bias to the electrostatic chuck to deposit a doped diamond-like carbon film on the substrate, the doped diamond-like carbon film having a density greater than 2.6 g/cc and a stress less than -500 MPa, the doped diamond-like carbon film comprising 45 atomic % to 95 atomic % sp3 ^hybridized carbon atoms;
The method includes: The method of claim 1, wherein the doped diamond-like carbon film has a density between 2.7 g/cc and 12 g/cc. The method of claim 1, wherein the dopant compound comprises a metal dopant comprising tungsten, molybdenum, cobalt, nickel, vanadium, hafnium, zirconium, tantalum, or any combination thereof. 2. The method of claim 1, wherein the dopant compound comprises tungsten hexafluoride, tungsten hexacarbonyl, molybdenum pentachloride, cyclopentadienyl dicarbonyl cobalt, dicobalt hexacarbonyl butyl acetylene (CCTBA), bis(cyclopentadienyl) cobalt, bis(methylcyclopentadienyl) nickel, vanadium pentachloride, zirconium tetrachloride, or any combination thereof . The method of claim 1, wherein the dopant compound comprises a nonmetallic dopant comprising boron, silicon, germanium, nitrogen, phosphorus, or any combination thereof. 10. The method of claim 1 , wherein the dopant compound comprises disilane, diborane, triethylborane, silane, disilane, trisilane, germane, ammonia, hydrazine, phosphine, adducts thereof, or any combination thereof. 2. The method of claim 1, wherein the doped diamond-like carbon film comprises between 0.1 atomic % and 20 atomic % of the dopant. The method of claim 1 , wherein the doped diamond-like carbon film comprises between 50 atomic % and 90 atomic % ^sp3 hybridized carbon atoms. The method of claim 1, wherein the hydrocarbon compound comprises ethylene, propene, methane, butene, 1,3-dimethyladamantane, bicyclo[2.2.1]hepta-2,5-diene, adamantine, norbornene, or any combination thereof. The method of claim 1 , wherein the deposition gas further comprises helium, argon, xenon, neon, nitrogen (N ₂ ), hydrogen (H ₂ ), or any combination thereof. The method of claim 1 , wherein the process space is maintained at a pressure between 5 mTorr and 100 mTorr and the substrate is maintained at a temperature between 0 ° C. and 50 ° C. The method of claim 1, wherein the doped diamond-like carbon film has an elastic modulus greater than 150 GPa. The method of claim 1, wherein generating the plasma at the substrate further comprises applying a second RF bias to the electrostatic chuck. The method of claim 13, wherein the electrostatic chuck has a chucking electrode and an RF electrode separate from the chucking electrode, and the first RF bias is applied to the RF electrode and the second RF bias is applied to the chucking electrode. 14. The method of claim 13 , wherein the first RF bias is provided at a frequency between 350 KHz and 100 MHz and at a power between 10 Watts and 3,000 Watts, and the second RF bias is provided at a frequency between 350 KHz and 100 MHz and at a power between 10 Watts and 3,000 Watts. 1. A method for processing a substrate, comprising:
flowing a deposition gas including a hydrocarbon compound and a dopant compound into a process space of a process chamber having a substrate disposed on an electrostatic chuck, the electrostatic chuck having a chucking electrode and an RF electrode separated from the chucking electrode, the process space being maintained at a pressure between 0.5 mTorr and 10 Torr;
generating a plasma at the substrate by applying a first RF bias to the RF electrode and a second RF bias to the chucking electrode to deposit a doped diamond-like carbon film on the substrate, the doped diamond-like carbon film having a density of greater than 2.6 g/cc to 12 g/cc and a stress of -600 MPa to -300 MPa, the doped diamond-like carbon film comprising 50 atomic % to 90 atomic % sp ³ hybridized carbon atoms ;
The method includes: The method of claim 16, wherein the doped diamond-like carbon film has a density between 3 g/cc and 10 g/cc. The method of claim 16, wherein the dopant compound comprises a metal dopant comprising tungsten, molybdenum, cobalt, nickel, vanadium, hafnium, zirconium, tantalum, or any combination thereof. The method of claim 16, wherein the dopant compound comprises a nonmetallic dopant comprising boron, silicon, germanium, nitrogen, phosphorus, or any combination thereof. 1. A method for processing a substrate, comprising:
flowing a deposition gas including a hydrocarbon compound and a dopant compound into a process space of a process chamber having a substrate disposed on an electrostatic chuck, the electrostatic chuck having a chucking electrode and an RF electrode separated from the chucking electrode, the process space being maintained at a pressure between 0.5 mTorr and 10 Torr;
generating a plasma at the substrate by applying a first RF bias to the RF electrode and a second RF bias to the chucking electrode to deposit a doped diamond-like carbon film on the substrate, the doped diamond-like carbon film having a density of greater than 2.6 g/cc to 12 g/cc and a stress of -600 MPa to -300 MPa;
forming a patterned photoresist layer over the doped diamond-like carbon film;
Etching the doped diamond-like carbon film in a pattern corresponding to the patterned photoresist layer;
Etching the pattern into the substrate;
The method includes:

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