High bias deposition of high quality gapfill

Abstract

To provide a gapfill deposition method and a diamond-like carbon gapfill that realize processes for filling narrow trenches with a high quality dielectric gapfill.SOLUTION: A method for forming a high quality gapfill in a feature of a substrate comprises: positioning a substrate in a process chamber; applying a chucking voltage to an electrostatic chuck to clamp the substrate to the electrostatic chuck; generating plasma at a horizontal surface of the substrate by applying a first RF bias to the electrostatic chuck; supplying a gapfill precursor into a processing space so as to form the gapfill in the substrate feature; and, after forming the gapfill on the substrate, de-chucking the substrate.SELECTED DRAWING: Figure 8

Description

[Technical Field]

[0001] FIELD OF THE DISCLOSURE

[0001] This disclosure relates generally to methods for depositing thin films, and more particularly to a process for filling narrow trenches with high quality dielectric gap fill materials. [Background technology]

[0002]

[0002] Miniaturization of semiconductor circuit elements has reached a point where feature sizes of 45 nm, 32 nm, 28 nm, and even 20 nm are being manufactured on an industrial scale. As dimensions shrink, new challenges arise for process steps, such as filling the gaps between circuit elements with various materials. As the width between elements continues to shrink, the gaps between elements often become taller and narrower. This makes it more difficult to fill the gaps without causing the gap-filling material to stick, resulting in voids and weak seams. Conventional chemical vapor deposition (CVD) techniques often result in overgrowth of material at the top of the gap before the gap is completely filled. This can lead to voids and seams where the deposited material is prematurely separated by the overgrowth. This problem is sometimes referred to as breadloafing.

[0003] One solution to the breadloafing problem has been to form a nascently-flowable film using a gap-filling precursor and a plasma-excited precursor combined in a plasma-free substrate processing region. The post-deposition flowability allows the film to fill gaps without seams or voids using this chemical vapor deposition technique. Such chemical vapor deposition has been found to produce better gap-filling properties than spin-on-glass (SOG) or spin-on-dielectric (SOD) processes. While the deposition of flowable films deposited by CVD has fewer breadloafing issues, such techniques are still unavailable for some types of materials.

[0004] While flowable CVD techniques have represented important breakthroughs in filling tall, narrow (i.e., high aspect ratio) gaps with other gap-filling materials, there remains a need for technologies capable of seamlessly filling such gaps with high-quality dielectric materials. For example, previous flowable carbon-based gap films contained significant amounts of oxygen and silicon. These elements significantly alter the properties of carbon-based gap films.

[0005]

[0005] Therefore, there is a need for precursors and methods for depositing high quality interstitial films. Summary of the Invention

[0006] One or more embodiments of the present disclosure are directed to a gap-fill deposition method that includes positioning a substrate on an electrostatic chuck within a processing space of a processing chamber. The substrate has a substrate surface including at least one feature. The at least one feature extends a depth from the substrate surface to a bottom surface. The at least one feature has an opening width at the substrate surface defined by a first sidewall and a second sidewall. While the processing space is maintained at a pressure between about 0.5 mTorr and about 10 Torr, a gap-fill precursor is flowed into the processing space from a gas supply assembly spaced above the electrostatic chuck. A plasma is generated in the processing space by applying a first RF bias to the electrostatic chuck to deposit gap-fill material within the at least one feature of the substrate. The gap-fill material is substantially void-free.

[0007] An additional embodiment of the present disclosure is directed to a gap-fill deposition method including positioning a substrate on a first electrode within a processing space of a processing chamber. The substrate has a substrate surface including at least one feature. The at least one feature extends a certain depth from the substrate surface to a bottom surface. The at least one feature has an opening width in the substrate surface defined by a first sidewall and a second sidewall. The processing chamber further includes a second electrode positioned above the first electrode and the substrate. The second electrode has a surface including a secondary electrode emission material, the secondary electrode emission material including one or more of a silicon-containing material or a carbon-containing material. A gap-fill precursor is flowed into the processing space. A first RF power is applied to at least one of the first electrode and the second electrode. A gap-fill material is formed in the at least one feature of the substrate. The gap-fill material is substantially void-free.

[0008] A further embodiment of the present disclosure is directed to a diamond-like carbon gap filler in a feature of a substrate, the gap filler having a density of about 1.8 g / cm 3 to about 2.5 g / cm 3 Density in the range of about 50% to about 90% sp 3 The feature has hybridized carbon atoms and a stress of less than 100 MPa. The feature extends to a depth from the surface to a bottom surface of the substrate. The feature has an opening width at the substrate surface defined by a first sidewall and a second sidewall. The ratio of the depth to the opening width of the feature is greater than or equal to approximately 10:1.

[0009]

[0009] So that the above-mentioned features of the present disclosure can be understood in detail, a more detailed description of the present disclosure, briefly summarized above, can be had by reference to embodiments, some of which are illustrated in the accompanying drawings. It should be noted, however, that the accompanying drawings illustrate only typical embodiments of the present disclosure and therefore should not be considered to limit the scope of the present disclosure, since the present disclosure may also admit of other equally effective embodiments. [Brief explanation of the drawings]

[0010] [Figure 1] 1 shows a schematic diagram of an example of a deposition apparatus in which electron beam plasma techniques can be used to practice some embodiments of the present disclosure. [Figure 2] FIG. 1 shows a schematic diagram of another example of a deposition apparatus in which electron beam plasma techniques can be used to practice some embodiments of the present disclosure. [Figure 3] FIG. 1 illustrates a process flow diagram of a method for forming a gap filler according to some embodiments of the present disclosure. [Figure 4A] FIG. 1 illustrates a process flow diagram of a method for forming a gap filler according to some embodiments of the present disclosure. [Figure 4B] FIG. 1 illustrates a process flow diagram of a method for forming a gap filler according to some embodiments of the present disclosure. [Figure 5A-B] 1A-1D illustrate cross sections of a substrate before and after processing in accordance with one or more embodiments of the present disclosure. [Figure 6A] 1 shows a schematic cross-sectional view of a deposition system that can be used to practice some embodiments of the present disclosure. [Figure 6B] FIG. 1 shows a schematic cross-sectional view of another deposition system that can be used to practice some embodiments of the present disclosure. [Figure 7] 6C shows a schematic cross-sectional view of an electrostatic chuck that can be used in the apparatus of FIG. 6A or FIG. 6B in which some embodiments of the present disclosure can be used. [Figure 8] 1 illustrates a flow diagram of a method for forming high quality gap fill material in features of a substrate in accordance with one or more embodiments of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0011]

[0019] For ease of understanding, where possible, identical reference numerals have been used to designate identical elements common to the figures. It is intended that elements and features of one embodiment may be beneficially incorporated in other embodiments without further description.

[0012]

[0020] As used herein and in the appended claims, the terms "substrate" and "wafer" are used interchangeably and both refer to a surface or portion of a surface upon which a process acts. It will also be appreciated by those skilled in the art that when reference is made to a substrate, it may refer to only a portion of the substrate unless the context clearly indicates otherwise. Furthermore, when reference is made to deposition on a substrate, it may refer to both a bare substrate and a substrate upon which one or more films or features have been deposited or formed.

[0013]

[0021] As used herein, "substrate" refers to any substrate or material surface formed on a substrate on which film processing is performed during a manufacturing process. For example, substrate surfaces on which processing can be performed include materials such as silicon, silicon oxide, strained silicon, silicon-on-insulator (SOI), carbon-doped silicon oxide, silicon nitride, doped silicon, germanium, gallium arsenide, glass, sapphire, and any other materials such as metals, metal nitrides, metal alloys, and other conductive materials, depending on the application. Substrates include, but are not limited to, semiconductor wafers. Substrates may undergo pretreatment processes, in which the substrate surface may be polished, etched, reduced, oxidized, hydroxylated (or otherwise generate or graft target chemical moieties to impart chemical functionality), annealed, and / or baked. In addition to film processing directly on the surface of the substrate itself, in the present disclosure, any of the disclosed film processing steps may also be performed on underlying layers formed on the substrate, as disclosed in more detail below. And the term "substrate surface" is intended to include such underlying layers, as the context indicates. Thus, for example, when a film / layer or partial film / layer is deposited on a substrate surface, the exposed surface of the newly deposited film / layer is the substrate surface. What a given substrate surface includes depends on what film is being deposited and the particular chemistry used.

[0014]

[0022] As used herein and in the appended claims, the terms "reactive gas," "precursor," "reactant," and the like are used interchangeably to refer to gases that contain species that react with the substrate surface. For example, a first "reactive gas" may simply be adsorbed on the surface of the substrate and available for further chemical reaction with a second reactive gas.

[0015]

[0023] As used herein, the term "about" means "approximately" or "nearly" and refers to a variation of no more than ±15% of the numerical value in relation to a stated numerical value or range. For example, values ​​that vary by ±14%, ±10%, ±5%, ±2%, or ±1% fall within the definition of "about."

[0016]

[0024] The following disclosure describes techniques for the deposition of high-quality gap-fill material into features of a substrate. Specific details are presented in the following description and in FIGS. 1 through 8 to provide a thorough understanding of various implementations of the present disclosure. Other details describing well-known structures and systems often associated with plasma processing and gap-fill material deposition are not presented in the following disclosure to avoid unnecessarily obscuring the description of the various embodiments.

[0017]

[0025] 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 present disclosure. Furthermore, further embodiments of the present disclosure may be practiced without some of the details described below.

[0018]

[0026] The implementations described herein are described below with reference to PECVD processes that can be performed using any suitable thin film deposition system. Examples of suitable systems include the 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, California. Other tools capable of performing PECVD processes can also be adapted to benefit from the embodiments described herein. Furthermore, any system that enables the PECVD processes described herein can be used advantageously. The apparatus descriptions described herein are exemplary and should not be understood or interpreted as limiting the scope of the present disclosure.

[0019]

[0027] The gap filler materials described herein can also be deposited in a process chamber having a multi-frequency capacitively coupled plasma (CCP) configuration surrounded by ceramic walls. The ceramic walls have an inductively coupled coil outside, allowing the plasma to be inductively enhanced. The process chamber has an upper electrode powered by one or more RF generators. The upper electrode can also function as a gas distribution showerhead. To adjust film uniformity, source gases can also be injected laterally into the process chamber. The process chamber further includes a bottom electrode on which the wafer is positioned. The bottom electrode is also powered by an RF generator, and the driving frequency depends on the selected deposition scheme.

[0020]

[0028] In some embodiments, the gap-fill precursor is introduced into the processing chamber through either a showerhead electrode or a sidewall injection. The processing chamber typically includes a top electrode (e.g., a showerhead electrode), a bottom electrode (e.g., a pedestal), and an ICP coil surrounding a portion of the processing chamber. The gap-fill precursor may be diluted with an inert gas (e.g., Ar or He) to increase the plasma density. Before the plasma is generated, a stable operating pressure (e.g., about 0.1 mTorr to several Torr) may be established in the processing chamber by a gate valve above the vacuum pump. RF power is applied to at least one of the top electrode, the bottom electrode, and the ICP coil. Depending on the power scheme, the top electrode, the bottom electrode, and the ICP coil may be powered simultaneously, or two of the three may be powered simultaneously. The applied RF frequency ranges from several hundred kHz to several tens of MHz. Additionally, multiple frequencies may be applied to the top or bottom electrode to optimize the ion flux and energy incident on the substrate. After the desired deposition time, the power is turned off, terminating the deposition.

[0021]

[0029] The power supply configurations for the top electrode, bottom electrode, and ICP coil may be any of the following power supply configurations: In some embodiments, only the top electrode is powered; The top electrode may be driven by multiple frequencies simultaneously (e.g., about 2 MHz and about 40 MHz); In some embodiments, both the top electrode and the ICP are powered; ICP can be used as a means to further lower k, increase deposition rate, or adjust uniformity; In some embodiments, only the bottom electrode is powered; The bottom electrode is either high frequency driven (e.g., greater than 13 MHz, e.g., 60 MHz) or high and low frequency driven in this configuration; In some embodiments, the bottom electrode and top electrode are powered simultaneously; In some embodiments, the lower electrode and ICP are powered simultaneously.

[0022]

[0030] In some embodiments, the top electrode has an electrode surface made of a high secondary electron emission material, such as silicon or carbon. When ions collide with the top electrode, secondary electrons emitted by the ion collisions are accelerated by the plasma sheath, thereby gaining high energy. These energetic secondary electrons are emitted downward like an electron beam and are very efficient at ionizing and dissociating hydrocarbon molecules. The gap between the top and bottom electrodes may be increased to increase the probability of collisions.

[0023]

[0031] Current gap filler applications primarily utilize flowable films, which are amorphous in nature but have properties that differ from similar bulk films. In many cases, the properties of the bulk film are preferable to those of the flowable gap filler. Therefore, there is a need for gap fillers, specifically carbon (diamond-like) films and other dielectric materials (e.g., Si, SiN, SiO), that have properties similar to the bulk materials. For diamond-like carbon materials, the bulk properties required for gap fillers include, but are not limited to, high density and high modulus (e.g., higher sp3 content, more diamond-like properties) and low stress (e.g., <-500 MPa).

[0024]

[0032] Some embodiments described herein provide methods for producing carbon gap fillers with high density (e.g., >1.8 g / cc), high modulus (e.g., >150 GPa), and low stress (e.g., <-500 MPa). The carbon gap fillers produced according to some embodiments described herein not only have low stress, but also have a high sp3 carbon content.

[0025]

[0033] In some embodiments, the gap fill materials described herein may be formed by a chemical vapor deposition (plasma-enhanced and / or thermal) process using a gap fill precursor. In some embodiments, the gap fill precursor comprises a hydrocarbon and the gap fill material comprises a diamond-like carbon material. In some embodiments, the hydrocarbon is selected from the group consisting of C2H2, C3H6, CH4, C4H8, 1,3-dimethyladamantane, bicyclo[2.2.1]hepta-2,5-diene (2,5-norbornadiene), adamantine (C 10 H 16 ), norbornene (C7H 10 ), and combinations thereof. In some embodiments, the gap fill precursor comprises a silicon-containing species and the gap fill material comprises a dielectric material. In some embodiments, the dielectric material comprises one or more of silicon, silicon oxide, or silicon nitride.

[0026]

[0034] The gap-fill deposition process may be carried out at a temperature ranging from -50°C to 600°C. The gap-fill deposition process may be carried out in a process volume at a pressure ranging from 0.1 mTorr to 10 Torr. The gap-fill precursor may further include any one of He, Ar, Xe, N2, H2, or any combination thereof.

[0027]

[0035] In some embodiments, to improve film quality, the gap-fill precursor may further include an etchant gas, such as Cl, CF, or NF. A plasma (e.g., a capacitively coupled plasma) may be formed from either a top electrode and a bottom electrode, or a side electrode. The electrodes may be formed from a single powered electrode, dual powered electrodes, or more electrodes with multiple frequencies (e.g., without limitation, 350 kHz, 2 MHz, 13.56 MHz, 27 MHz, 40 MHz, 60 MHz, and 100 MHz) used alternatively or simultaneously in a CVD system with any or all of the reactive gases listed herein to deposit the gap-fill material within the features of the substrate.

[0028]

[0036] In some embodiments, hydrogen radicals are provided through the RPS to selectively etch sp2 hybridized carbon atoms, resulting in a further increase in the fraction of sp3 hybridized carbon atoms in the gap fill material.

[0029]

[0037] FIG. 1 shows a schematic diagram of an example of a processing apparatus 100 that can use electron beam plasma techniques to implement some embodiments of the present disclosure. The electron beam plasma chamber has a vacuum chamber body defining a processing chamber 100, including a cylindrical sidewall 102. The processing chamber 100 is divided into an upper chamber 100a and a lower chamber 100b by a grid filter 104. The lower chamber 100b is a drift space because no substantial electric field exists therein in the absence of an applied bias voltage. A ceiling 106 overlies the upper chamber 100a and supports an electrode 108. In some embodiments, the electrode 108 is formed from a process-compatible material, such as silicon, carbon, a silicon carbide compound, or a silicon oxide compound. In some embodiments, the electrode 108 is formed from a metal oxide (e.g., aluminum oxide, yttrium oxide, or zirconium oxide). The ceiling 106 and electrode 108 may be disk-shaped. The bottom surface of the electrode 108 faces the grid filter 104 and is exposed to the interior of the upper chamber 100a. In some embodiments, an insulator or dielectric ring 109 surrounds the electrode 108.

[0030]

[0038] In certain embodiments, the electrode 108 is formed of a carbon-containing material, which can help provide a carbon source during the gap-filler deposition process. Therefore, the electrode 108 may be consumed after a number of gap-filler deposition processes have been performed. The consumption of irradiated material from the electrode 108 may help form a carbon gap-filler layer with high film density. Therefore, periodic replacement of the electrode 108 may be performed to ensure process reliability and reproducibility.

[0031]

[0039] In some embodiments, the electrode 108 functions as a showerhead assembly that supplies process gases into the processing chamber 100. In some embodiments, the electrode 108 has a plurality of openings 108-1 for supplying process gases into the processing chamber 100. The gases are supplied from an array of process gas supplies 114 through an array of valves (not shown).

[0032]

[0040] A workpiece support pedestal 110 for supporting a workpiece (e.g., a substrate 111) in the lower chamber 100b has a workpiece support surface 110a facing the grid filter 104 and may be axially movable by a lift servo 112. In some embodiments, the workpiece support pedestal 110 includes an insulating puck 195 that forms the workpiece support surface 110a, a workpiece electrode 196 inside the insulating puck 195, and a chucking voltage supply 199 connected to the workpiece electrode 196. In addition, a base layer 194 underlying the insulating puck 195 has internal passages 107 for circulating a heat medium (e.g., a liquid) from a circulating supply 198. The circulating supply 198 may function as a heat sink or a heat source.

[0033]

[0041] An RF source power generator 120 having a VHF frequency (e.g., 160 MHz) and a low-frequency RF source power generator 122 having a frequency below the VHF range or below the HF range (e.g., in the MF or LF range, such as 2 MHz) are coupled to the electrode 108 via an RF feed conductor 123 through an impedance matcher 124. The RF source power generators 120, 122 are typically capable of generating RF signals having frequencies from about 0.4 kHz to about 300 MHz and powers from about 0 watts to about 10,000 watts. In some embodiments, the impedance matcher 124 is adapted to provide impedance matching at the different frequencies of the RF source power generators 120 and 122 and to provide filtering to isolate the power generators from each other. The output power levels of the RF source power generators 120, 122 are independently controlled by a controller 126. As described in more detail below, power from the RF source power generators 120, 122 is coupled to the electrode 108. In some embodiments, the ceiling 106 is conductive and in electrical contact with the electrode 108 , and power from the impedance matcher 124 is conducted through the ceiling 106 to the electrode 108 .

[0034]

[0042] In some embodiments, the sidewall 102 is formed of metal and is grounded. In some embodiments, the surface area of ​​the grounded interior surface within the upper chamber 100a is at least twice the surface area of ​​the electrode 108. In some embodiments, the grounded interior surface within the processing chamber 100 may be coated with a process-compatible material (e.g., silicon, carbon, silicon carbide compounds, or silicon oxide compounds). In alternative embodiments, the grounded interior surface within the processing chamber 100 may be coated with a material such as aluminum oxide, yttrium oxide, or zirconium oxide.

[0035]

[0043] In some embodiments, RF source power generator 120 may be replaced with two separately controlled VHF power generators 120a and 120b. VHF power generator 120a has an output frequency in the lower range of the VHF band (e.g., 30 MHz to 150 MHz), while VHF power generator 120b has an output frequency in the higher range of the VHF band (e.g., 150 MHz to 300 MHz). Controller 126 can control plasma ion density by selecting the ratio between the output power levels of VHF power generators 120a and 120b. The two VHF power generators 120a and 120b can be used to control the radial plasma uniformity within the upper chamber 100a by selecting the gap (the distance between the electrode 108 and the grid filter 104) of the upper chamber 100a, such that a lower VHF frequency inherently results in a periphery-high radial distribution of plasma ion density within the upper chamber 100a, and a higher VHF frequency inherently results in a center-high radial distribution of plasma ion density. With such a selection, the power levels of the two VHF power generators 120a, 120b are then set to a ratio that optimizes the uniformity of the radial distribution of plasma ion density.

[0036]

[0044] In some embodiments, the ceiling 106 is a support for the electrode 108 and includes an insulating layer 150 that includes a chucking electrode 152 facing the electrode 108. A DC chucking voltage supply 154 is coupled to the chucking electrode 152 via a feed conductor 155 to electrostatically secure the electrode 108 to the ceiling 106. A DC blocking capacitor 156 may be connected in series with the output of the impedance matcher 124. A controller 126 may control the DC chucking voltage supply 154. In some embodiments, an RF feed conductor 123 from the impedance matcher 124 may be connected to the electrode support or the ceiling 106 rather than directly to the electrode 108. In such embodiments, RF power from the RF feed conductor 123 may be capacitively coupled from the electrode support to the electrode 108. In some embodiments, an upper gas injector 130 supplies process gas into the upper chamber 100a via a first valve 132. In some embodiments, a lower gas injector 134 supplies process gas into the lower chamber 100a via a second valve 136. Gas is supplied from an array of process gas supplies 138 through an array of valves 140, which may include, for example, the first valve 132 and the second valve 136. In some embodiments, the gas species and gas flow rates into the upper chamber 100a and the lower chamber 100b are individually controllable. A controller 126 can control the array of valves 140. In some embodiments, an inert gas is supplied into the upper chamber 100a and a process gas is supplied into the lower chamber 100b. The flow rate of the inert gas can be selected to substantially prevent convection or diffusion of gas from the lower chamber 100b into the upper chamber 100a, thereby providing substantial chemical isolation of the upper chamber 100a.

[0037]

[0045] In some embodiments, plasma can be generated in the upper chamber 100a for various bulk and surface processes involving energetic ion bombardment on the inner surface of the upper electron emission electrode 108. The ion bombardment energy and plasma density of the electrode 108 are functions of both the RF source power generators 120 and 122. The ion bombardment energy of the electrode 108 can be substantially controlled by the low-frequency power from the RF source power generator 122. The plasma density in the upper chamber 100a can also be substantially controlled (enhanced) by the VHF power from the RF source power generator 120. Energetic secondary electrons can be emitted from the inner surface of the electrode 108. The flux of energetic electrons from the emission surface can comprise an electron beam, have a direction substantially perpendicular to the inner surface of the electrode 108, and have a beam energy close to the ion bombardment energy of the electrode 108, which can typically be in the range of about 10 eV to 5000 eV (e.g., at least greater than 100 eV). The bombardment cross-section of various processes depends on the electron energy. At low energies, the cross section for excitation (and dissociation in molecular gases) is larger than the cross section for ionization, while at high energies the opposite is true. One or more RF power levels can be advantageously selected to target various inelastic electron collision processes.

[0038]

[0046] In some embodiments, a side window 170 in the sidewall 102 faces the upper chamber 100a and is formed of a material (e.g., quartz or aluminum oxide) into which RF power can be inductively coupled. An inductive coil antenna 172 surrounds the side window 170 and is driven by an optional RF source power generator 174 via an impedance matcher 176. The RF source power generator 174 applied to the inductive coil antenna 172 is controlled between approximately 200 watts (W) and approximately 10 kilowatts. The frequency of the inductively coupled power applied to the inductive coil antenna 172 can be between 2 MHz and approximately 13 MHz. A remote plasma source 197 can introduce plasma species into the lower chamber 100b. In embodiments having an RF source power generator 174 and an inductive coil antenna 172, the plasma density in the upper chamber 100a can be substantially controlled (enhanced) by the RF power from the RF source power generator 174. In one embodiment, the RF source power generator 174 and the induction coil antenna 172 assist in providing an impact force to sputter off material from the electrode 108, which in turn assists in depositing material onto the surface of the substrate 111 disposed on the workpiece support pedestal 110.

[0039]

[0047] In some embodiments, the grid filter 104 may be flat, disk-shaped, and coaxial with the sidewall 102 . The grid filter 104 is formed with an array of a plurality of apertures 104-1. In some embodiments, the axial thickness T of the grid filter 104 and the diameter "d" of the plurality of apertures 104-1 are selected to facilitate the flow of energetic directed beam electrons through the grid filter 104 while impeding the flow of non-beam (low energy) electrons and plasma ions through the grid filter 104. Here, the ratio of grid filter hole area to total grid filter area may be maximized. The energetic electron flux (electron beam) passes through the grid filter 104 into the lower chamber 100b and may generate a plasma through various electron collision processes within the lower chamber 100b.

[0040]

[0048] The plasma generated by the electron beam in the lower chamber 100b may have different characteristics than the plasma in the upper chamber 100a. The grid filter 104 may function as a filter that substantially electrically isolates the upper and lower chambers 100a and 100b from each other. In some embodiments, the grid filter 104 is formed from a conductive or semiconductive material and may be connected to ground or electrically floating. In some embodiments, the grid filter 104 is formed from a non-conductive material. In some embodiments, the grid filter 104 may be coated with a process-compatible material such as silicon, carbon, silicon carbide compounds, or silicon oxide compounds. In some embodiments, the grid filter 104 may be coated with a material such as aluminum oxide, yttrium oxide, or zirconium oxide. In some embodiments, the plasma generated in the upper chamber 100a may have a high electron density and / or a high electron temperature, resulting in energetic ions bombarding the electrode 108.

[0041]

[0049] At least a portion of the electron beam, consisting of secondary electron flux emitted from the electrode 108 by energetic ion bombardment of the electrode surface, propagates through the grid filter 104 into the lower chamber 100b, generating a low electron temperature plasma in the lower chamber 100b, the plasma density of which depends on the beam energy and beam flux, as well as other factors (e.g., pressure and gas composition). Upon leaving the plasma region of the lower chamber 100b, the energetic beam electrons may impinge on the substrate 111 or workpiece support pedestal 110. The plasma left behind can easily discharge any resulting surface charge caused by the electron beam flux.

[0042]

[0050] In some embodiments where higher electron beam flux or higher electron beam density is required, the grid filter 104 can be removed or eliminated to help the secondary electron beam flux emitted from the electrode 108 reach the substrate 111 or workpiece support pedestal 110 at a faster rate, as shown in Figure 2. Alternatively, the grid filter 104 may be removed or eliminated in the processing chamber 100 due to any process concerns and requirements, as shown in Figure 2.

[0043]

[0051] In some embodiments, an electronegative or electron-attaching gas (e.g., chlorine) is supplied into the chamber, RF and / or VHF power is applied to the electrode 108, RF power is optionally applied to the inductive coil antenna 172, remote plasma source (RPS) power is optionally applied to the remote plasma source (RPS) 197, a plasma is generated in the upper chamber 100a, and an accelerating voltage is generated on the electrode 108 relative to ground and the plasma. The resulting energetic ion collisions with the electrode 108 generate secondary electron emissions from the electrode surface, which constitute an electron beam flux from the electrode surface. The grid filter 104 allows at least a portion of the electron beam to propagate through the grid filter 104 into the lower chamber 100b, while simultaneously preventing at least a portion of the non-beam electrons and plasma ions from passing through the grid filter 104. This generates a low electron temperature plasma in the lower chamber 100b. The resulting low electron temperature plasma in an electronegative gas such as chlorine in the lower chamber 100b can produce a highly electronegative plasma, which has a density of negative ions much higher than the electron density and approaches the density of positive ions. Such a plasma is often referred to as an ion-ion plasma.

[0044]

[0052] A magnetic field oriented substantially axially, substantially parallel to the electron beam, may optionally be used to aid in guiding the electron beam, thereby improving beam transport through the upper chamber 100a, the grid filter 104, and / or the lower chamber 100b. A low-frequency bias voltage or a low-repetition-frequency arbitrary waveform may be applied to the workpiece support pedestal 110 (e.g., the workpiece electrode 196) to selectively or alternately extract positive and / or negative ions from the plasma and accelerate these ions to a desired energy level to impact the surface of the substrate 111 for etching, cleaning, deposition, or other material modification. Radicals generated (a) in the upper chamber 100a, (b) by the electron beam in the lower chamber 100b, (c) by application of a bias voltage to the workpiece support pedestal 110, or (d) by the remote plasma source (RPS) 197 may convect or diffuse to the substrate 111 and participate in reactions on the workpiece surface.

[0045]

[0053] In some embodiments, a relatively inert gas (e.g., helium or argon) is supplied into the upper chamber 100a, an electronegative or electron-attaching gas (e.g., sulfur hexafluoride or fluorocarbon) is flowed into the lower chamber 100b, RF and / or VHF power is applied to the electrode 108, RF power is optionally applied to the inductive coil antenna 172, RPS power is optionally applied to the remote plasma source 197, a plasma is generated in the upper chamber 100a, and an accelerating voltage is generated on the electrode 108 relative to ground and the plasma. The resulting energetic ion collisions with the electrode 108 generate secondary electron emissions from the electrode surface, which constitute an electron beam flux from the electrode surface. The grid filter 104 allows at least a portion of the electron beam to propagate through the grid filter 104 into the lower chamber 100b while simultaneously preventing at least a portion of the non-beam electrons and plasma ions from passing through the grid filter 104. This generates a low electron temperature plasma in the lower chamber 100b.

[0046]

[0054] The resulting low electron temperature plasma in the electronegative gas in the lower plasma chamber can produce a highly electronegative plasma, which has a much higher density of negative ions than the electron density, approaching the density of positive ions, commonly referred to as an ionic plasma.

[0047]

[0055] In some embodiments, the grid filter 104 is a gas distribution plate having internal gas passages 105a and gas jets 105b. The internal gas passages 105a can be connected to an array of valves 140.

[0048]

[0056] In some embodiments, the RF bias power generator 142 is coupled to the workpiece electrode 196 of the workpiece support pedestal 110 through an impedance matcher 144. In further embodiments, a waveform adjustment processor 147 may be connected between the output of the impedance matcher 144 and the workpiece electrode 196. The waveform adjustment processor 147 varies the waveform generated by the RF bias power generator 142 to a desired waveform. The ion energy of the plasma near the substrate 111 is controlled by the waveform adjustment processor 147. In some embodiments, the waveform adjustment processor 147 generates a waveform whose amplitude is maintained at a level corresponding to a desired ion energy level for a specific portion of each RF cycle. The controller 126 may control the waveform adjustment processor 147.

[0049]

[0057] In some embodiments, an RF power generator 146 having a VHF or HF frequency (e.g., 11 MHz to 60 MHz) and an RF power generator 148 having a frequency below the VHF range or below the HF range (e.g., in the MF or LF range, such as 0.4 kHz to 10 MHz) are coupled to the workpiece electrode 196 via an impedance matcher 144. The RF power generators 146, 148 are typically capable of generating RF signals having frequencies from about 0.4 kHz to about 300 MHz and powers from about 0 watts to about 10,000 watts. In some embodiments, the RF power generators 146, 148 are RF bias power generators. In some embodiments, the RF power generators 146, 148 are RF source power generators. In some embodiments, the impedance matcher 124 is adapted to provide impedance matching at different frequencies for the RF power generators 146 and 148 and to provide filtering to isolate the power generators from each other. The output power levels of the RF power generators 146, 148 are independently controlled by the controller 126. As described below, power from the RF power generators 146, 148 is coupled to the workpiece electrode 196. As previously mentioned, a VHF generator may also be used.

[0050]

[0058] In some embodiments, magnets 160 surround the processing chamber 100. In some embodiments, the magnets include a pair of magnets 160-1, 160-2 adjacent to the upper chamber 100 a and the lower chamber 100 b, respectively. In some embodiments, the pair of magnets 160-1, 160-2 provides an axial magnetic field suitable for confining the electron beam propagating from the upper chamber 100 a to the lower chamber 100 b.

[0051]

[0059] In some embodiments, the flow of energetic electrons to the substrate 111 is blocked by a magnetic field having a predominantly radial component (i.e., perpendicular to the electron beam flow direction) in the region between the grid filter 104 and the substrate 111. This magnetic field may be generated by one of the magnets 160-1 or 160-2, or by another magnet or set of magnets.

[0052]

[0060] In some embodiments, the ceiling 106 includes an internal passage 178 for conducting a thermally conductive liquid or medium therein. The internal passage 178 is connected to a heat transfer medium circulating supply 180. The heat transfer medium circulating supply 180 acts as a heat sink or a heat source. The mechanical contact between the electrode 108 and the ceiling 106 is sufficient to maintain a high thermal conductance between the electrode 108 and the ceiling 106. In the embodiment shown in FIG. 1 , the force of the mechanical contact is regulated by an electrostatic clamping force provided by the DC chucking voltage supply 154.

[0053]

[0061] 3 shows a flow diagram of a method 300 for forming a gap fill material in a substrate feature according to one or more embodiments of the present disclosure. Figures 4A and 4B are cross-sectional views of a substrate illustrating a sequence for forming a gap fill material in a substrate feature according to method 300.

[0054]

[0062] The method 300 begins at operation 310, in which a substrate 111 is provided in a processing chamber (e.g., processing chamber 100 shown in FIG. 1 or FIG. 2). Suitable substrates are described elsewhere in this disclosure.

[0055]

[0063] In operation 320, a gap fill precursor is supplied into the processing chamber 100 in preparation for forming a gap fill in the substrate feature. The gap fill precursor may be supplied from a process gas supply 138 through an array of valves 140 to gas injectors 130, 134, each flowing into the processing chamber 100.

[0056]

[0064] In some embodiments, the gap-filling precursor comprises a hydrocarbon. Suitable hydrocarbons are described in detail elsewhere in this disclosure. Additional suitable hydrocarbon compounds include aliphatic and aromatic hydrocarbons.

[0057]

[0065] Alicyclic hydrocarbons include, for example, cyclopropane, cyclobutane, cyclopentane, cyclopentadiene, toluene, etc. Aromatic hydrocarbons include, for example, benzene, styrene, toluene, xylene, pyridine, ethylbenzene, acetophenone, methyl benzoate, phenyl acetate, phenol, cresol, furan, etc. Additionally, α-terpinene, cymene, 1,1,3,3-tetramethylbutylbenzene, t-butyl ether, t-butyl ethylene, methyl methacrylate, and t-butyl furfuryl ether may be suitable.

[0058]

[0066] In some embodiments, the hydrocarbon is selected from propene, acetylene, ethylene, propylene, butylene, toluene, and α-terpinene. In some embodiments, the hydrocarbon is selected from C2H2, C3H6, CH4, C4H8, 1,3-dimethyladamantane, bicyclo[2.2.1]hepta-2,5-diene (2,5-norbornadiene), adamantine (C 10 H 16 ), norbornene (C7H 10 ), and combinations thereof.

[0059]

[0067] In some embodiments, multiple hydrocarbon compounds can be mixed and delivered to the processing chamber as gap-fill precursors. A mixture of two or more hydrocarbon compounds can be used to deposit the gap-fill material.

[0060]

[0068] In some embodiments, the hydrocarbon comprises or consists essentially of methane (CH4), hi some embodiments, the gap-fill precursor comprises methane and at least one of propene, acetylene, or ethylene.

[0061]

[0069] In some embodiments, a gap-fill precursor, such as methane, may be supplied to the gas mixture at a rate of about 50 sccm to about 1000 sccm. An inert gas (e.g., Ar gas or He gas) may be supplied to the gas mixture at a rate of about 10 sccm to about 1000 sccm. Hydrogen gas may be supplied to the gas mixture at a rate of about 100 sccm to about 500 sccm. Oxygen gas may be supplied to the gas mixture at a rate of about 0 sccm to about 200 sccm. Nitrogen gas may be supplied to the gas mixture at a rate of about 0 sccm to about 400 sccm. Additionally, an additional hydrocarbon may be supplied to the gas mixture at a flow rate between about 100 sccm and about 2000 sccm.

[0062]

[0070] In some embodiments, adjustable flow ratios and species can be controlled and supplied to the processing chamber 100 from various locations (e.g., the upper gas injector 130 or the lower gas injector 134, and the electrode) to maximize radical dissociation and plasma density below or above the grid filter 104. For example, if a higher plasma density is desired in the upper chamber 100a to increase the beam electron flux, an inert gas such as Ar or He may be supplied through the upper gas injector 130. This can promote electrode collisions, reduce molecular gas density near the electrode 108, and increase the local plasma density and beam electron flux. In contrast, if dissociation of hydrogen molecules is desired (e.g., to increase the purity of the resulting film), a hydrogen-containing gas is supplied through the upper gas injector 130 to promote hydrogen radical formation and drive out impurities in the processing chamber and the resulting gap fill material, while reducing the local plasma density.

[0063]

[0071] Optionally, in operation 330, the pressure in the processing chamber 100 is stabilized for a predetermined RF-on delay time period. The predetermined RF-on delay period is a fixed period defined as the time between the introduction of the gap-fill precursor into the processing chamber 100 and the striking or generation of plasma in operation 340. Any suitable fixed time delay may be used to achieve the desired conditions. The length of the RF-on delay period is typically selected so that the gap-fill precursor does not, or does not substantially, begin to thermally decompose in the processing chamber 100. The process of operation 330 may be performed simultaneously, sequentially, or partially overlapping with the processes of operations 320 and 340.

[0064]

[0072] In such embodiments, the gap fill precursor may be introduced into the processing chamber 100 for a longer period of time, such as between about 5 seconds and about 30 seconds (e.g., about 15 seconds), which may vary depending on the size of the substrate. It is believed that the flow of the gap fill precursor before striking the plasma provides for continuous thermal and pressure stabilization of the processing chamber 100. In some embodiments, the gap fill precursor is then flowed into the processing chamber 100 for about 0.5 seconds to about 5 seconds (e.g., about 1 second to about 2 seconds) before striking the RF plasma in operation 340 (the flow time may vary as long as it is long enough for the gap fill precursor to begin to reach the interior space of the processing chamber 100).

[0065]

[0073] In operation 340, after the gap-fill precursor is supplied into the processing chamber, RF power is supplied to at least one of the upper electrode (e.g., electrode 108), the lower electrode (e.g., workpiece electrode 196), and / or the inductive coil antenna (e.g., inductive coil antenna 172). In operation 340, after the gas mixture is supplied into the processing chamber, a first RF source power is generated from RF source power generators 120, 122 and applied to electrode 108, thereby generating a plasma and a secondary electron beam. The secondary electron beam from electrode 108 can generate a cold plasma. This cold plasma is at a temperature below 100 degrees Celsius, for example, that irradiates the surface of the substrate to form a gap-fill material thereon. Additionally, a second optional RF power can be applied to inductive coil antenna 172 through RF source power generator 174 to add inductively coupled power. The generated inductively coupled power may increase radical flux to the substrate and increase ion flux (or beam flux) incident on the electrons in the upper chamber 100a, producing a high density beam electrons. The inductively coupled power also reduces the sheath voltage to the electrode 108, thus reducing the beam energy. Additionally, a third optional RF power may be applied to the workpiece electrode 196 to optimize the ion flux and energy incident on the substrate. The third RF power may be generated by the RF power generators 146, 148 and / or the additional RF bias power generator 142.

[0066]

[0074] The second source power (e.g., inductively coupled power) generated by the RF source power generator 174 and applied to the inductive coil antenna 172 is typically controlled between about 1 kilowatt and about 10 kilowatts. The frequency of the inductively coupled power applied to the inductive coil antenna 172 may be between 2 MHz and about 13 MHz. In some embodiments, the inductively coupled power may be eliminated or optionally applied as needed. For example, a process pressure of between 20 mTorr and about 20 Torr may be further utilized to form the gap fill material. It is believed that the electron beam plasma, along with the secondary electron beam utilized during the deposition process, may provide higher ion bombardment. This higher ion bombardment may enhance the dissociation of the ions and electron beam energy from the gas mixture, resulting in a gap fill with a robust film structure.

[0067]

[0075] In some embodiments, only the upper electrode (e.g., electrode 108) is powered during operation 340. For example, a first RF source power generated from at least one of RF source power generators 120, 120a, 120b, 122 is applied to electrode 108 and controlled in a range between 1 kilowatt and approximately 10 kilowatts. Note that the frequency of RF source power generators 120, 120a, 120b, 122 can be between 0.4 MHz and approximately 300 MHz. In this example, power is applied only to the upper electrode (e.g., power is not applied to either the lower electrode (e.g., workpiece electrode 196) or the inductive coil antenna (e.g., inductive coil antenna 172)). In some embodiments, the frequency applied to the upper electrode is between 0.4 MHz and approximately 300 MHz. In some embodiments, a high frequency (e.g., between approximately 11 MHz and 60 MHz) is applied to the upper electrode. In some embodiments, a low frequency (e.g., between about 0.4 kHz and 10 MHz) is applied to the upper electrode, and in some embodiments, multiple frequencies (e.g., 2 MHz from low frequency RF source power generator 122 and 40 MHz from VHF power generator 120a) are applied to the upper electrode.

[0068]

[0076] In some embodiments, during operation 340, power is supplied to both the upper electrode (e.g., electrode 108) and the inductive coil antenna (e.g., inductive coil antenna 172). For example, a first RF source power generated from at least one of RF source power generators 120, 120a, 120b, 122 is applied to the upper electrode and controlled in a range between 1 kilowatt and approximately 10 kilowatts, and a second RF source power is applied to the inductive coil antenna and controlled in a range between approximately 1 kilowatt and approximately 10 kilowatts. In this example, power is applied to both the upper electrode and the inductive coil antenna (e.g., no power is applied to the lower electrode (e.g., workpiece electrode 196)). In some embodiments, the frequency applied to the upper electrode is between approximately 0.4 MHz and approximately 300 MHz, and the frequency applied to the inductive coil antenna is between approximately 2 MHz and approximately 13 MHz. In some embodiments, a high frequency (e.g., between about 11 MHz and 60 MHz) is applied to the upper electrode, and the frequency applied to the inductive coil antenna is between about 2 MHz and about 13 MHz. In some embodiments, a low frequency (e.g., between about 0.4 kHz and 10 MHz) is applied to the upper electrode, and the frequency applied to the inductive coil antenna is between about 2 MHz and about 13 MHz. In some embodiments, multiple frequencies (e.g., 2 MHz from low frequency RF source power generator 122 and 40 MHz from VHF power generator 120a) are applied to the upper electrode, and the frequency applied to the inductive coil antenna is between about 2 MHz and about 13 MHz. Without being bound by theory, it is believed that ICP can be used to improve the deposition rate and tailor the uniformity of the deposited gap fill material.

[0069]

[0077] In some embodiments, power is supplied only to the lower electrode (e.g., workpiece electrode 196) during operation 340. In embodiments in which power is supplied to the lower electrode, the drive frequency may include a high-frequency component. For example, a first RF power (bias or source) generated from at least one of RF power generators 146, 148 and / or additional RF bias power generator 142 is applied to the lower electrode and controlled in a range between 1 kilowatt and approximately 10 kilowatts. Note that the frequencies of RF power generators 146, 148 and RF bias power generator 142 may be between 0.4 MHz and approximately 300 MHz. In this example, power is applied only to the lower electrode (e.g., power is not applied to either the upper electrode (e.g., electrode 108) or the inductive coil antenna (e.g., inductive coil antenna 172)). In some embodiments, the frequency applied to the lower electrode is between 0.4 MHz and approximately 300 MHz. In some embodiments, a high frequency (e.g., between about 11 MHz and 60 MHz) is applied to the lower electrode, hi some embodiments, multiple frequencies (e.g., 2 MHz from RF power generator 148 and 40 MHz from RF power generator 146) are applied to the lower electrode.

[0070]

[0078] In some embodiments, using any of the aforementioned conditions, power is simultaneously supplied to both the upper electrode (e.g., electrode 108) and the lower electrode (e.g., workpiece electrode 196) during operation 340. For example, RF source power generated from at least one of RF source power generators 120, 120a, 120b, 122 is applied to the upper electrode and controlled in a range between 1 kilowatt and approximately 10 kilowatts, and a second RF power (bias or source) is applied to workpiece electrode 196 and controlled in a range between approximately 1 kilowatt and approximately 10 kilowatts. In this example, power is applied to both electrode 108 and workpiece electrode 196 (e.g., no power is applied to the inductive coil antenna (e.g., inductive coil antenna 172)). In some embodiments, the frequency applied to electrode 108 is between approximately 0.4 MHz and approximately 300 MHz, and the frequency applied to workpiece electrode 196 is between approximately 0.4 MHz and approximately 300 MHz. In some embodiments, multiple frequencies (eg, 2 MHz from a low frequency RF power generator and 40 MHz from a VHF power generator) are applied to the electrode 108 and the workpiece electrode 196 .

[0071]

[0079] In some embodiments, during operation 340, power is supplied to both the inductive coil antenna (e.g., inductive coil antenna 172) and the lower electrode (e.g., workpiece electrode 196). In this example, power is applied to both the inductive coil antenna 172 and the workpiece electrode 196 (e.g., no power is applied to the upper electrode (e.g., electrode 108)). In some embodiments, the frequency applied to the inductive coil antenna 172 is between about 2 MHz and about 13 MHz and is controlled in a range between 1 kilowatt and about 10 kilowatts, and the frequency applied to the workpiece electrode 196 is between about 0.4 MHz and about 300 MHz and is controlled between about 1 kilowatt and about 10 kilowatts.

[0072]

[0080] In some embodiments, multiple frequencies (eg, 2 MHz from a low frequency RF power generator and 40 MHz from a VHF power generator) are applied to at least one of the inductive coil antenna 172 and the workpiece electrode 196 .

[0073]

[0081] In some embodiments, during operation 340, power is supplied to the upper electrode (eg, electrode 108), the lower electrode (eg, workpiece electrode 196), and the inductive coil antenna (eg, inductive coil antenna 172).

[0074]

[0082] During operation 340, the substrate temperature can be controlled between room temperature (e.g., 20° C.) and about 1000° C. During operation 340, the spacing between the substrate and the showerhead can be controlled from about 1000 mils to about 15000 mils. During operation 340, the process pressure can be maintained, for example, between 0.1 mTorr and about 20 Torr.

[0075]

[0083] In operation 350, after the deposition process is performed with the process parameters adjusted in operation 340, a gap fill material is then formed in the substrate feature. In some embodiments, the gap fill material formed here is configured to have a density of about 1.5 g / cc to about 2.0 g / cc. In some embodiments, the gap fill material has a stress of 100 MPa or less.

[0076]

[0084] Embodiments of the present disclosure include methods for depositing gap filler materials using a combination of plasma-induced CVD and physical vapor deposition (PVD). The density, hardness, and stress of the deposited gap filler material can be adjusted by the relative weights of the CVD and PVD components.

[0077]

[0085] Referring to FIGS. 1 and 2, the top electrode (e.g., electrode 108) is driven by one or more RF generators and optionally functions as a gas distribution showerhead. The surface of the top electrode contains carbon, and as the plasma sheath accelerates the ions, carbon atoms are sputtered and deposited on the wafer surface during the PVD process. The bottom electrode (e.g., workpiece electrode 196) is also powered by an RF generator. If the source gas contains hydrocarbon gas, any RF power applied to the top and / or bottom electrodes dissociates the hydrocarbon gas, thus generating CVD components. One advantage of applying bias RF power to the CVD components is that hydrocarbon ions can be accelerated toward the wafer surface and implanted into the carbon layer, increasing the density and hardness of the carbon film. Furthermore, the powerful ion bombardment reduces film stress and creates cross-links between the PVD and CVD layers, thereby helping to improve film morphology. However, when only top electrode RF power is present, the density of the deposited film is typically soft and low.

[0078]

[0086] In some embodiments of the present disclosure, the gap-fill precursor is introduced into the processing chamber either through a showerhead electrode or sidewall injection. To increase plasma density, the gap-fill precursor may be diluted with an inert gas (e.g., Ar or He). Before the plasma is generated, a stable operating pressure (e.g., about 0.1 mTorr to several Torr) may be established in the processing chamber by a gate valve above a vacuum pump. RF power is applied to at least one of the top electrode, the bottom electrode, and the ICP coil. The top electrode, the bottom electrode, and the ICP coil may be powered simultaneously, or two of the three may be powered simultaneously, depending on the power supply configuration described previously in this specification. The applied RF frequency ranges from several hundred kHz to several tens of MHz. Additionally, multiple frequencies may be applied to the top or bottom electrode to optimize the ion flux and energy incident on the substrate.

[0079]

[0087] After the desired CVD deposition time, the gap-fill precursor can be stopped, and the inert gas can continue to flow into the chamber. A stable operating pressure (0.1 mTorr to tens of mTorr) can be established by a gate valve above the vacuum pump. Typically, the PVD process pressure is very low (e.g., between about 1 mTorr and about 10 mTorr) to maximize ion energy. RF power can be applied to the upper and lower electrodes during PVD deposition. Bottom RF power may be absent during PVD deposition. To maximize sputtering yield, the top electrode can be powered from multiple RF frequency sources. Magnetic fields can be used to further increase plasma density at low pressures, thereby increasing the carbon sputtering rate. Power can be applied to the bottom electrode to introduce moderate ion bombardment, which densifies the film and cross-links the PVD and CVD layers. Under RF sputtering conditions, the deposited film is typically free of particle issues. The PVD and CVD processes are repeatedly performed until the desired amount of gap-fill material is deposited. A sequence of deposition, PVD, then CVD, or deposition, CVD, then PVD may be used.

[0080]

[0088] In some embodiments, the PVD and CVD processes are performed simultaneously. In some embodiments, a CVD film may also deposit on the carbon target surface on the upper electrode, interfering with the sputtering process. In some embodiments, an inert purge gas is flowed through the upper electrode or injected from the ambient into the upper chamber (e.g., upper chamber 100a), and a carbon source gas is injected into the lower chamber (lower chamber 100b). This minimizes back-diffusion of the carbon source gas into the upper electrode and reduces carbon film deposition on the upper electrode surface.

[0081]

[0089] In some embodiments, during the CVD process, the powered upper electrode further emits secondary electrons due to ion bombardment. The secondary electrons are accelerated by the plasma sheath and have energies of approximately several hundred eV to keV. Because the electron impact ionization cross section of hydrocarbon gases typically peaks at several hundred eV, the secondary electrons can significantly contribute to hydrocarbon gas ionization, which in turn contributes to increasing film density. Therefore, multiple RF frequencies can be applied to the upper electrode, thereby optimizing the secondary electron emission yield while maintaining the sheath voltage at approximately several hundred eV.

[0082]

[0090] An oxygen plasma cleaning process can be performed between the CVD and PVD steps to remove any deposition film that may have been deposited during the CVD process from the surface of the upper electrode. This allows the sputtering process to begin with a clean carbon surface. An oxygen plasma can be formed by flowing an oxygen-containing gas, optionally in an inert gas, into the processing chamber. The oxygen-containing gas can be selected from the group consisting of N2O, O2, O3, H2O, and combinations thereof. The optional inert gas can be selected from the group consisting of helium, argon, and combinations thereof. During the oxygen plasma cleaning process, RF power is supplied to at least one of the upper electrode (e.g., electrode 108) and / or the inductive coil antenna (e.g., inductive coil antenna 172).

[0083]

[0091] In some embodiments of the oxygen plasma cleaning process, RF power generated by at least one of the RF source power generators 120, 120a, 120b, and 122 is applied to the electrode 108 and controlled in a range between 1 kilowatt and approximately 10 kilowatts. Note that the frequency of the RF source power generators 120, 120a, 120b, and 122 can be between 0.4 MHz and approximately 300 MHz. In some embodiments in which a second RF source power is used, the second RF source power (e.g., inductively coupled power) generated by the RF source power generator 174 and applied to the coil antenna 172 is typically controlled between approximately 1 kilowatt and approximately 10 kilowatts. The frequency of the inductively coupled power applied to the coil antenna 172 can be between 2 MHz and approximately 13 MHz. For example, a process pressure between approximately 20 mTorr and approximately 20 Torr can also be utilized to perform the oxygen plasma cleaning process. The oxygen plasma cleaning process can be performed for a time sufficient to remove residue from the surface of the electrode 108.

[0084]

[0092] 4A and 4B show a process flow diagram of one embodiment of a method 500 for forming a gap filler, according to some embodiments described herein.

[0085]

[0093] Method 500 begins at operation 510, in which a substrate 111 is provided in a processing chamber (e.g., the electron beam plasma processing chamber 100) shown in Figure 1 or Figure 2. The substrate 111 may have a substantially flat surface, an uneven surface, or a structure formed thereon.

[0086]

[0094] In operation 520, a gap-fill precursor is supplied into the processing chamber 100 in preparation for forming a gap-fill material on the substrate 111 by a chemical vapor deposition (CVD) process. In some embodiments, the gap-fill precursor is supplied from a process gas supply 138 through an array of valves 140 to gas injectors 130, 134, each flowing into the processing chamber 100. In some embodiments, the gap-fill precursor may be supplied from a process gas supply 114 and flow to the electrode 108.

[0087]

[0095] Gap-fill precursors may include hydrocarbons, as described elsewhere in this disclosure, and inert gases.

[0088]

[0096] In some embodiments, adjustable flow ratios and species can be controlled and supplied to the processing chamber 100 from various locations (e.g., the upper gas injector 130 or the lower gas injector 134, and the electrode 108) to maximize radical dissociation and plasma density below or above the grid filter 104. For example, if a higher plasma density is desired in the upper chamber 100a to increase the beam electron flux, an inert gas such as Ar or He may be supplied through the upper gas injector 130. This can promote electrode collisions, reduce molecular gas density near the electrode 108, and increase the local plasma density and beam electron flux. In contrast, if dissociation of hydrogen molecules is desired (e.g., to increase the purity of the resulting film), a hydrogen-containing gas is supplied through the upper gas injector 130 to promote hydrogen radical formation and drive out impurities in the processing chamber and the resulting gap fill material, while reducing the local plasma density.

[0089]

[0097] Optionally, in operation 530, the pressure in the processing chamber is stabilized for a predetermined RF-on delay period, similar to operation 330. Any suitable fixed time delay may be used to achieve the desired conditions. The process of operation 530 may be performed simultaneously, sequentially, or partially overlapping with the processes of operation 520 and operation 540. In some embodiments, the pressure is stabilized at a pressure of about 0.1 mTorr to about 5 Torr.

[0090]

[0098] In such embodiments, the gap fill precursor may be introduced into the processing chamber 100 for a longer period of time, such as between about 5 seconds and about 30 seconds (e.g., about 15 seconds), which may vary depending on the size of the substrate. It is believed that the flow of the gap fill precursor before striking the plasma provides for continuous thermal and pressure stabilization of the processing chamber 100. In some embodiments, the gap fill precursor is flowed into the processing chamber 100 for about 0.5 seconds to about 5 seconds (e.g., about 1 second to about 2 seconds) before striking the RF plasma in operation 540 (the flow time may vary as long as it is long enough for the gap fill precursor to begin to reach the processing chamber 100).

[0091]

[0099] In operation 540, after the gap-fill precursor is supplied into the processing chamber, RF power is supplied to at least one of the upper electrode (e.g., electrode 108), the lower electrode (e.g., workpiece electrode 196), and / or the inductive coil antenna (e.g., inductive coil antenna 172). Operation 540 may be performed using any of the power supply configurations described in connection with operation 340. In operation 540, after the gas mixture is supplied into the processing chamber, a first RF source power may be generated from RF source power generators 120, 122 and applied to electrode 108, thereby generating a plasma and a secondary electron beam. The secondary electron beam from electrode 108 may generate a cold plasma. This cold plasma may be at a temperature below 100 degrees Celsius, for example, that irradiates the surface of the substrate to form a gap-fill material thereon. Additionally, a second optional RF power may be applied to coil antenna 172 through RF source power generator 174 to add inductively coupled power. The generated inductively coupled power may increase radical flux to the substrate and increase ion flux (or beam flux) incident on the electrons in the upper chamber 100a, producing a high density beam electrons. The inductively coupled power also reduces the sheath voltage to the electrode 108, thus reducing the beam energy. Additionally, a third optional RF power may be applied to the workpiece electrode 196 to optimize the ion flux and energy incident on the substrate. The third RF power may be generated by the RF power generators 146, 148 and / or the additional RF bias power generator 142.

[0092]

[0100] In some embodiments in which a first RF source power is used, the first RF source power generated from at least one of the RF source power generators 120, 120a, 120b, 122 is applied to the electrode 108 and is controlled in a range between 1 kilowatt and approximately 10 kilowatts. Note that the frequency of the RF source power generators 120, 120a, 120b, 122 can be between 0.4 MHz and approximately 300 MHz. In some embodiments in which a second RF source power is used, the second RF source power (e.g., inductively coupled power) generated by the RF source power generator 174 and applied to the coil antenna 172 is typically controlled between approximately 1 kilowatt and approximately 10 kilowatts. The frequency of the inductively coupled power applied to the coil antenna 172 can be between 2 MHz and approximately 13 MHz. In embodiments in which power is supplied to the lower electrode, the drive frequency can include a low frequency component, a high frequency component, or a mixture of both low and high frequency components. For example, RF bias power generated from RF bias power generator 142 is applied to workpiece electrode 196 and controlled in a range between 1 kilowatt and about 10 kilowatts. Note that the frequency of RF bias power generator 142 can be from 0.4 MHz to about 300 MHz. In some embodiments, multiple frequencies (e.g., 2 MHz from a low frequency RF power generator and 40 MHz from a VHF power generator) are applied to workpiece electrode 196.

[0093]

[0101] For example, a process pressure between 20 mTorr and about 20 Torr can be further utilized to form the gap fill material. It is believed that the electron beam plasma, along with the secondary electron beam utilized during the deposition process, can provide higher ion bombardment. This higher ion bombardment can enhance the dissociation of the ions and electron beam energy from the gas mixture, resulting in the formation of a gap fill with a robust film structure.

[0094]

[0102] During operation, the substrate temperature can be controlled between room temperature (e.g., 20° C.) and about 1000° C. The spacing between the substrate and the showerhead can be controlled from about 200 mils to about 15000 mils (e.g., from about 200 mils to about 1000 mils).

[0095]

[0103] As discussed elsewhere, the electron beam plasma and secondary electron beam supplied from the electrode 108 are accelerated by the electrode sheath and thus gain additional energy as they enter the bulk plasma. These accelerated electrons provide sufficient high energy to efficiently dissociate hydrogen from molecules and generate sufficient hydrogen radicals to extract hydrogen impurities from carbon films, such as gap fillers formed on the substrate 111, thereby forming high-purity gap fillers. The accelerated secondary beam electrons generate a low-temperature plasma, or cold plasma, above the substrate 111 (in the lower chamber region 100b below the grid filter 104). Low electron temperatures often have low electron energies of less than 1 eV (e.g., less than 0.5 eV). Therefore, sufficient low-energy electrons from the cold plasma are generated to efficiently dissociate vibrational hydrogen molecules to generate hydrogen radicals, increasing the hydrogen radical flux to the substrate surface.

[0096]

[0104] Furthermore, when the accelerated secondary electron beam emitted from the electrode 108 reaches the substrate surface, the high energy (e.g., approximately hundreds to thousands of electron volts (eV)) carried by the accelerated secondary electron beam can induce surface reactions. These surface reactions can, for example, excite carbon sp3 surface states, form gap fillers on the substrate 111, and break weak (or undesirable) carbon sp or sp2 bonds or even C-H bonds, thereby increasing sp3 bonds and promoting the formation of diamond-like carbon materials rather than amorphous or other carbon structures. The carbon atoms bonded in the gap fillers can be primarily formed in sp3 carbon, with four single bonds pointing to the corners of a tetrahedron bonded to other carbon elements. Undesirable sp2 hybridized carbon, with two single bonds and one double bond (e.g., three bonds pointing to the corners of a triangle), often results in an amorphous film structure rather than the desired diamond-like structure. The amount of hydrogen termination bonds and the degree of any missing or dangling carbon bonds contained in sp3- or sp2-hybridized carbon affect how tightly these carbon atoms are networked and compressed, which in turn determines the film density and stress. The gap filler is configured to form with full sp3 hybridization and zero hydrogen content when all carbon atoms are fully interconnected. In one embodiment, the accelerated secondary electron beam can have a beam energy greater than 100 eV.

[0097]

[0105] In operation 550, after the deposition process is performed with the process parameters adjusted in operation 540, a gap fill material is then formed in the substrate feature.

[0098]

[0106] Optionally, after operation 550 is completed, an optional chamber purge process can be performed to remove any residual gases and by-products from the gap-fill formation process from the chamber. During the chamber purge process, a purge gas (e.g., an inert gas such as argon or nitrogen) can be supplied into the processing chamber 100 from at least one of the electrode 108, the upper gas injector 130, and the lower gas injector 134. In some embodiments, the flow of the gap-fill precursor used during operation 540 is stopped while the inert gas used during operation 540 continues to flow and acts as a purge gas. The pressure within the processing chamber 100 can be controlled using a valve system, which controls the rate at which exhaust gases are drawn from the chamber.

[0099]

[0107] In some embodiments, after operation 550 is completed, an oxygen plasma cleaning process similar to the oxygen plasma cleaning process described above is performed between the CVD and PVD processes to remove any film deposited on the surface of the upper electrode during the CVD process, thereby cleaning the carbon surface of electrode 108 before starting the PVD process.

[0100]

[0108] In operation 570, the pressure in the processing chamber is stabilized for a predetermined RF-on delay period, similar to operation 330. Any suitable fixed time delay may be used to achieve the desired conditions. The process of operation 530 may be performed simultaneously, sequentially, or partially overlapping with the processes of operation 520 and operation 540. In some embodiments, the pressure is stabilized at a pressure of about 0.1 mTorr to about 5 Torr.

[0101]

[0109] The predetermined RF-on delay time period is a fixed time delay defined as the time period between the execution of the CVD process and the striking or creation of the plasma in operation 580. Any suitable fixed time delay may be used to achieve the desired pressure conditions. The length of the RF-on delay time period is typically selected so that the pressure in the processing chamber is stabilized to a desired pressure for the physical chemical vapor deposition process. The process of operation 570 may be performed simultaneously, sequentially, or partially overlapping with the processes of operation 560 and operation 580. In some embodiments, the pressure is stabilized at a pressure of about 0.1 mTorr to about 50 mTorr (e.g., between about 1 mTorr and about 10 mTorr). Typically, the PVD process pressure is quite low to maximize ion energy.

[0102]

[0110] After the desired CVD deposition time, in operation 580, RF power is applied to the upper electrode (e.g., electrode 108) while flowing an inert gas into the processing chamber. The inert gas may be the same inert gas used during the CVD deposition process or a different inert gas. In some embodiments, the gap-fill precursor used during the CVD process is turned off while the inert gas continues to flow into the chamber. RF power is applied to at least the upper electrode during the PVD process. To maximize the sputtering yield, the upper electrode may be powered by multiple RF frequency sources. In some embodiments, RF power is also applied to the lower electrode (e.g., workpiece electrode 196) during the PVD process. Power can be supplied to the lower electrode to introduce moderate ion bombardment, which densifies the film and cross-links the PVD and CVD layers. In some embodiments, a magnetic field can be used to further increase the plasma density at low pressures, thereby increasing the sputtering rate of carbon. For example, the magnetic field can be applied by magnets 160-1 and 160-2. The magnetic field can have a magnetic strength of 1000 Gauss or less (eg, from about 20 Gauss to about 700 Gauss, or from about 100 Gauss to about 500 Gauss).

[0103]

[0111] In some embodiments, only the upper electrode (e.g., electrode 108) is powered during the PVD process of operation 580. For example, a first RF source power generated from at least one of RF source power generators 120, 120a, 120b, 122 is applied to electrode 108 and controlled in a range between 1 kilowatt and approximately 10 kilowatts. Note that the frequency of RF source power generators 120, 120a, 120b, 122 can be between 0.4 MHz and approximately 300 MHz. In this example, power is applied only to the upper electrode (e.g., power is not applied to either the lower electrode (e.g., workpiece electrode 196) or the inductive coil antenna (e.g., inductive coil antenna 172)). In some embodiments, the frequency applied to the upper electrode is between 0.4 MHz and approximately 300 MHz. In some embodiments, a high frequency (e.g., between approximately 11 MHz and 60 MHz) is applied to the upper electrode. In some embodiments, a low frequency (e.g., between about 0.4 kHz and 10 MHz) is applied to the upper electrode, and in some embodiments, multiple frequencies (e.g., 2 MHz from low frequency RF source power generator 122 and 40 MHz from VHF power generator 120a) are applied to the upper electrode.

[0104]

[0112] In yet another example, using any of the conditions described above, power is simultaneously supplied to both the upper electrode (e.g., electrode 108) and the lower electrode (e.g., workpiece electrode 196) during operation 580. For example, RF source power generated from at least one of RF source power generators 120, 120a, 120b, 122 is applied to the upper electrode and controlled in a range between 1 kilowatt and approximately 10 kilowatts, and a second RF power (bias or source) is applied to the lower electrode 196 and controlled between approximately 1 kilowatt and approximately 10 kilowatts. In this example, power is applied to both electrode 108 and workpiece electrode 196 (e.g., no power is applied to the inductive coil antenna (e.g., inductive coil antenna 172)). In some embodiments, the frequency applied to electrode 108 is between approximately 0.4 MHz and approximately 300 MHz, and the frequency applied to workpiece electrode 196 is between approximately 0.4 MHz and approximately 300 MHz. In some embodiments, multiple frequencies (eg, 2 MHz from a low frequency RF power generator and 40 MHz from a VHF power generator) are applied to the electrode 108 and the workpiece electrode 196 .

[0105]

[0113] In operation 590, after the deposition process is performed with the process parameters adjusted in operation 580, carbon is sputtered into the gap fill material within the substrate 111.

[0106]

[0114] The CVD process (e.g., operations 520 through 550) and the PVD process (e.g., operations 560 through 590) may be performed iteratively until a desired amount of gap fill material is deposited. Furthermore, although the deposition sequence is described as CVD followed by PVD, PVD may also be followed by CVD.

[0107]

[0115] In some embodiments, the PVD and CVD processes are performed simultaneously. In this embodiment, a CVD film may also deposit on the carbon target surface on the upper electrode, interfering with the sputtering process. In some embodiments, an inert purge gas is flowed through the upper electrode or injected from the ambient air into the upper chamber (e.g., upper chamber 100a), and a carbon source gas is injected into the lower chamber (lower chamber 100b). This minimizes back-diffusion of the carbon source gas into the upper electrode and reduces carbon film deposition on the upper electrode surface.

[0108]

[0116] In some embodiments, the gap filler formed herein has a density of 2.0 g / cm 3 or more (for example, about 2.0 g / cm 3 to about 2.5 g / cm 3 In some embodiments, the gap filler has a stress of 500 MPa or less.

[0109]

[0117] In some embodiments, the temperature of the workpiece support pedestal 110 on which the substrate 111 is positioned may be used to control the stress of the deposited carbon film. The inventors have found that the temperature of the support pedestal can affect and be used to reduce film stress. For example, for a particular power / pressure / gas combination, when the support pedestal temperature is 60°C, the stress of the deposited gap filler is approximately -800 MPa. However, lowering the support pedestal temperature to 10°C reduces the stress of the deposited film to approximately -600 MPa. Additionally, helium flowing between the workpiece support surface 110a of the support surface and the backside of the substrate 111 can be used to adjust film stress. In some embodiments, the helium flows at a pressure of about 15 Torr to about 30 Torr, and the support pedestal temperature is set to a range of about 20°C to about 700°C.

[0110]

[0118] Thus, a method for forming a gap filler having a desired density with low stress is provided by an electron beam plasma deposition process. The method advantageously provides a gap filler having low stress and one or more desired mechanical properties, such as high density, high etch selectivity, or transparency. The improved mechanical properties of the gap filler result in high film quality while maintaining a predetermined range of film flatness and stress levels.

[0111]

[0119] FIG. 6A shows a schematic diagram of a substrate processing system 732 that can be used to perform gap-fill deposition according to one or more embodiments described herein. The substrate processing system 732 includes a processing chamber 700 coupled to a gas panel 730 and a controller 710. The processing chamber 700 generally includes a top wall 724, a side wall 701, and a bottom wall 722, which define a processing space 726. A substrate support assembly 746 is disposed within the processing space 726 of the processing chamber 700. The substrate support assembly 746 generally includes an electrostatic chuck 750 supported by a stem 760. The electrostatic chuck 750 can typically be fabricated from aluminum, ceramic, and other suitable materials. The electrostatic chuck 750 can be moved vertically within the processing chamber 700 using a displacement mechanism (not shown).

[0112]

[0120] A vacuum pump 702 is connected to a port formed in the bottom of the processing chamber 700. The vacuum pump 702 is used to maintain a desired gas pressure within the processing chamber 700. The vacuum pump 702 evacuates post-processing gases and process by-products from the processing chamber 700.

[0113]

[0121] The substrate processing system 732 may further include additional devices for controlling chamber pressure (e.g., valves such as throttle valves or isolation valves) positioned between the processing chamber 700 and the vacuum pump 702 to control the chamber pressure.

[0114]

[0122] A gas distribution assembly 720 having a plurality of apertures 728 is disposed on top of the processing chamber 700 above the electrostatic chuck 750. The apertures 728 of the gas distribution assembly 720 are utilized to introduce processing gases into the processing chamber 700. The apertures 728 may have various sizes, numbers, distributions, shapes, designs, and diameters to facilitate the flow of various processing gases for different process requirements. The gas distribution assembly 720 is connected to a gas panel 730. The gas panel 730 allows various gases to be supplied to the processing space 726 during processing. A plasma is formed from the processing gas mixture exiting the gas distribution assembly 720, which facilitates thermal decomposition of the processing gases and results in material deposition on the surface 791 of the substrate 790.

[0115]

[0123] The gas distribution assembly 720 and the electrostatic chuck 750 may form a spaced-apart electrode pair within the process space 726. One or more RF power sources 740, via an optional matching network 738, supply a bias potential to the gas distribution assembly 720 to facilitate plasma generation between the gas distribution assembly 720 and the electrostatic chuck 750. Alternatively, the RF power sources 740 and matching network 738 may be coupled to the gas distribution assembly 720, the electrostatic chuck 750, or both the gas distribution assembly 720 and the electrostatic chuck 750, or may be coupled to an antenna (not shown) located outside the process chamber 700. In some embodiments, the RF power sources 740 may generate power at frequencies of 350 KHz, 2 MHz, 13.56 MHz, 27 MHz, 40 MHz, 60 Mhz, or 100 MHz. In some implementations, the RF power source 740 can provide power between about 100 watts and about 3000 watts at frequencies between about 50 kHz and about 13.6 MHz, hi some implementations, the RF power source 740 can provide power between about 500 watts and about 1800 watts at frequencies between about 50 kHz and about 13.6 MHz.

[0116]

[0124] The controller 710 includes a central processing unit (CPU) 712, memory 716, and support circuits 714, which are utilized to control processing sequences and regulate gas flow from the gas panel 730. The CPU 712 may be any form of general-purpose computer processor that may be used in an industrial environment. Software routines may be stored in the memory 716 (e.g., random access memory, read-only memory, floppy or hard disk drive, or other form of digital storage). The support circuits 714 are conventionally coupled to the CPU 712 and may include cache, clock circuits, input / output systems, power supplies, etc.

[0117]

[0125] A controller that may be included in any of the described processing devices may have a processor, memory coupled to the processor, input / output devices coupled to the processor, and circuitry for communication between various electronic components. The memory may include one or more of transient memory (e.g., random access memory) and non-transient memory (e.g., storage).

[0118]

[0126] The memory or computer-readable medium of the processor may be one or more of readily available memories, such as random access memory (RAM), read-only memory (ROM), a floppy disk, a hard disk, or any other form of local or remote digital storage. The memory may hold a set of instructions operable by the processor to control system parameters and components. Support circuits are coupled to the CPU for supporting the processor in a conventional manner. The circuits may include, for example, cache, power supplies, clock circuits, input / output circuits, subsystems, etc.

[0119]

[0127] The processes are generally stored in memory as software routines. When executed by a processor, the software routines cause the processing chamber to perform the processes of the present disclosure. The software routines may be stored and / or executed by a second processor (not shown) located remotely from the hardware controlled by the processor. Some or all of the methods of the present disclosure may also be performed in hardware. Thus, the processes may be implemented in software and executed using a computer system in hardware (e.g., an application-specific integrated circuit or other type of hardware implementation), or a combination of software and hardware. When executed by a processor, the software routines transform a general-purpose computer into a special-purpose computer (controller). The special-purpose computer controls the operation of the chamber and performs the processes.

[0120]

[0128] Bidirectional communication between the controller 710 and the various components of the substrate processing system 732 is handled through a number of signal cables (collectively referred to as signal bus 718, some of which are shown in Figure 6A).

[0121]

[0129] 6B shows a schematic cross-sectional view of another substrate processing system 780 that can be used to practice embodiments described herein. The substrate processing system 780 is similar to the substrate processing system 732 of FIG. 6A, except that the substrate processing system 780 is configured to flow process gases from a gas panel 730 through a sidewall 701 across a surface 791 of a substrate 790. Additionally, the gas distribution assembly 720 shown in FIG. 6A has been replaced with an electrode 782. The electrode 782 may be configured for secondary electron generation. In some embodiments, the electrode 782 is a silicon-containing electrode.

[0122]

[0130] 7 shows a schematic cross-sectional view of a substrate support assembly 746 used in the processing system of FIGS. 6A and 6B , which can be used to practice some embodiments. Referring to FIG. 7 , an electrostatic chuck 750 can include an embedded heater element 770 suitable for controlling the temperature of a substrate 790 supported on an upper surface 792 of the electrostatic chuck 750. The electrostatic chuck 750 can be resistively heated by applying a current from a heater power supply 706 to the heater element 770. The heater power supply 706 can be coupled through an RF filter 816. The RF filter 816 can be used to protect the heater power supply 706 from RF energy. The heater element 770 can be made of nickel-chromium wire enclosed within a sheathed tube of a nickel-iron-chromium alloy (e.g., INCOLOY®). The current supplied by the heater power supply 706 is adjusted by the controller 710 to control the heat generated by the heater element 770, thereby maintaining the substrate 790 and electrostatic chuck 750 at a substantially constant temperature during film deposition. The supplied current can be adjusted to selectively control the temperature of the electrostatic chuck 750 between about −50° C. and about 600° C.

[0123]

[0131] 6A and 6B, in a conventional manner, a temperature sensor 772, such as a thermocouple, may be embedded in the electrostatic chuck 750 to monitor the temperature of the electrostatic chuck 750. The controller 710 uses the measured temperature to control the power supplied to the heater element 770 to maintain the substrate at a desired temperature.

[0124]

[0132] The electrostatic chuck 750 includes a chucking electrode 810. The chucking electrode 810 may be a mesh of a conductive material. The chucking electrode 810 may be embedded in the electrostatic chuck 750. The chucking electrode 810 is coupled to a chucking power supply 812. The chucking power supply 812, when energized, electrostatically clamps the substrate 790 to an upper surface 792 of the electrostatic chuck 750.

[0125]

[0133] The chucking electrode 810 may be configured as a monopolar or bipolar electrode, or may have another suitable configuration. The chucking electrode 810 may be coupled to a chucking power supply 812 through an RF filter 214. The chucking power supply 812 provides direct current (DC) power to electrostatically secure the substrate 790 to the upper surface 792 of the electrostatic chuck 750. The RF filter 214 prevents RF power utilized to form the plasma within the processing chamber 700 from damaging or causing electrical disturbances to electrical equipment outside the chamber during chucking. The electrostatic chuck 750 may be fabricated from a ceramic material such as AlN or Al2O3. Alternatively, the electrostatic chuck 750 may be fabricated from a polymer such as polyimide, polyetheretherketone, or polyaryletherketone.

[0126]

[0134] A power application system 220 is coupled to the substrate support assembly 746. The power application system 220 may include a heater power supply 706, a chucking power supply 812, a first radio frequency (RF) power supply 830, and a second RF power supply 840. An embodiment of the power application system 220 may further include a controller 710, a sensor device 850 in communication with the controller 710, and both the first RF power supply 830 and the second RF power supply 840.

[0127]

[0135] The controller 710 can further be utilized to control a plasma from the processing gas by applying RF power from the first RF power source 830 and the second RF power source 840 to deposit a layer of material on the substrate 790.

[0128]

[0136] As described above, the electrostatic chuck 750 includes a chucking electrode 810. In one embodiment, the chucking electrode 810 functions to chuck the substrate 790 while also functioning as a first RF electrode. The electrostatic chuck 750 may also include a second RF electrode 860, which, in conjunction with the chucking electrode 810, may apply RF power to regulate the plasma. The first RF power source 830 may be coupled to the second RF electrode 860, while the second RF power source 840 may be coupled to the chucking electrode 810. A first matching network and a second matching network may be provided for the first RF power source 830 and the second RF power source 840, respectively. The second RF electrode 860 may be a solid metal plate of a conductive material as shown. Alternatively, the second RF electrode 860 may be a mesh of a conductive material.

[0129]

[0137] The first RF power source 830 and the second RF power source 840 may generate power at the same frequency or at different frequencies. In some embodiments, one or both of the first RF power source 830 and the second RF power source 840 may individually generate power at a frequency from about 350 KHz to about 100 MHz (e.g., 350 KHz, 2 MHz, 13.56 MHz, 27 MHz, 40 MHz, 60 MHz, or 100 MHz). In some embodiments, the first RF power source 830 may generate power at a frequency of 13.56 MHz and the second RF power source 840 may generate power at a frequency of 2 MHz, or vice versa. RF power from one or both of the first RF power source 830 and the second RF power source 840 may be varied to adjust the plasma. For example, a sensor device 850 may be used to monitor RF energy from one or both of the first RF power source 830 and the second RF power source 840. Data from the sensor device 850 can be transmitted to the controller 710. The controller 710 can be utilized to vary the power applied by the first RF power source 830 and the second RF power source 840.

[0130]

[0138] The amount / proportion of sp3 hybridized carbon atoms in a diamond-like carbon material can vary from application to application. In some embodiments, the diamond-like carbon material may contain at least 40, 45, 50, 55, 60, 65, 70, 75, 80, or 85 percent sp3 hybridized carbon atoms. The diamond-like carbon material may contain up to 45, 50, 55, 60, 65, 70, 75, 80, 85, or 90 percent sp3 hybridized carbon atoms. The diamond-like carbon material may contain about 50 to about 90 percent sp3 hybridized carbon atoms. The diamond-like carbon material may contain about 60 to about 70 percent sp3 hybridized carbon atoms.

[0131]

[0139] Generally, the following exemplary deposition process parameters can be used to form gap fill material in substrate features: The wafer temperature can range from about −50° C. to about 350° C. (e.g., from about 10° C. to about 100° C., or from about 10° C. to about 50° C.). The chamber pressure can range from about 0.5 mTorr to about 10 Torr (e.g., from about 2 mTorr to about 50 mTorr, or between about 2 mTorr and about 10 mTorr). The flow rate of the gap fill precursor can range from about 10 sccm to about 1000 sccm (e.g., from about 100 sccm to about 200 sccm, or from about 750 sccm to about 200 sccm). The flow rates of the dilution gases can individually range 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). The spacing between the gas distribution assembly and the substrate can be from about 1000 to about 15000 mils (eg, from about 6000 to about 12000 mils, or from about 8000 to about 12000 mils).

[0132]

[0140] The gap fill material may be deposited to a thickness of about 5 Å to about 20,000 Å (e.g., about 900 Å to about 5,000 Å, between about 2,000 Å and about 9,000 Å, or between about 5 Å and about 200 Å). The above process parameters provide example process parameters for a 900 mm substrate in a deposition chamber available from Applied Materials, Inc. of Santa Clara, California.

[0133]

[0141] The gap filler may have a refractive index or n-value (n (at 633 nm)) greater than 2.0 (e.g., from about 2.0 to about 3.0, e.g., 2.3). The 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, e.g., 0.25).

[0134]

[0142] The diamond-like carbon material may have a stress (MPa) of less than about −900 MPa, such as from about −600 MPa to about −900 MPa, from about −600 MPa to about −500 MPa, for example, about −550 MPa.

[0135]

[0143] Diamond-like carbon material is approximately 1.8 g / cm 3 For example, about 2.0 g / cm 3 or more, or about 2.5 g / cm 3 For example, about 1.8 g / cm 3 to about 2.5 g / cm 3 The density (g / cc) may be

[0136]

[0144] The diamond-like carbon material may have an elastic modulus of greater than 750 GPa (eg, from about 200 to about 10 GPa).

[0137]

[0145] 8 shows a flow diagram of a method 900 for forming gap fill material in a substrate feature in accordance with one or more embodiments of the present disclosure. Figures 5A and 5B are cross-sectional views of a substrate illustrating a sequence for forming gap fill material in a substrate feature in accordance with method 900. It should also be understood that the steps shown in Figure 8 may be performed simultaneously and / or in a different order than that shown in Figure 8.

[0138]

[0146] Method 900 begins at operation 910. In operation 910, a substrate (e.g., substrate 10 shown in FIG. 5A) is positioned in a processing chamber (e.g., processing chamber 700 shown in FIG. 6A or 6B). Substrate 10 may be substrate 790 shown in FIGS. 6A, 6B, and 7. Substrate 10 may be positioned on an electrostatic chuck (e.g., upper surface 792 of electrostatic chuck 750).

[0139]

[0147] 5A shows a partial cross-sectional view of a substrate 10 having a feature 12. As used in this context, the term "feature" refers to any intentional surface irregularity. Suitable examples of features include, but are not limited to, trenches (having a top, two sidewalls, and a bottom), valleys (having a top and two sidewalls without a distinct bottom), and vias (having sidewalls extending downward from the surface with an open bottom or a bottom formed of a different material than the sidewalls).

[0140]

[0148] 5A and 5B show a substrate with a single feature for illustrative purposes, but one skilled in the art will understand that there may be more than one feature. The shape of feature 12 may be any suitable shape, including, but not limited to, trenches and cylindrical vias.

[0141]

[0149] Substrate 10 has a top surface 20. At least one feature 12 forms an opening in top surface 20. Feature 12 extends a depth D from top surface 20 to a bottom surface 30. Feature 12 has a first sidewall 14 and a second sidewall 16 that define an opening width W of feature 12. The open area formed by the sidewalls and the bottom is also referred to as a gap.

[0142]

[0150] In particular embodiments, feature 12 is a trench. The feature can have any suitable aspect ratio (ratio of feature depth D to feature width W). In some embodiments, the aspect ratio is about 5:1, 10:1, 15:1, 20:1, 25:1, 30:1, 35:1, or 40:1 or greater.

[0143]

[0151] The substrate 10 may be a carbon-based material, or any suitable insulating or conductive material as desired, and has disposed thereon features 12 that may be filled with gap filler material 50, as shown in FIG. 5B.

[0144]

[0152] 5A, the substrate 10 can have an upper surface 20. The upper surface 20 can be a substantially planar, uneven, or substantially flat surface (as shown) with structures formed thereon or additional features formed therein.

[0145]

[0153] In some embodiments, the substrate 10 is crystalline silicon (e.g., Si <100> or Si <111> The substrate 10 may be a material such as silicon dioxide, strained silicon, silicon germanium, doped or undoped polysilicon, doped or undoped silicon substrate, patterned or unpatterned silicon-on-insulator (SOI), carbon-doped silicon dioxide, silicon nitride, doped silicon, germanium, gallium arsenide, glass, sapphire, or the like. The substrate 10 may have various dimensions (e.g., 200 mm, 900 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 200 mm diameter, a 900 mm diameter, or a 450 mm diameter. In embodiments in which an SOI structure is utilized in the substrate 10, the substrate 10 may include a buried dielectric layer disposed in a silicon crystalline substrate. In the embodiments described herein, the substrate 10 may be a crystalline silicon substrate.

[0146]

[0154] It should be noted that the gap fill material may be formed on any surface or portion of the substrate 10 (including the top surface 20 ), inside or outside of features 12 present on the substrate 10 .

[0147]

[0155] In one or more embodiments, the gap filler material 50 is deposited such that substantially no seam is formed in the gap. A seam is formed where the thickness of the film approaches the top of the feature 12 before the feature 12 is filled with the film ("breadloafing"). The seam can be any gap, space, or void formed between the sidewalls 14, 16 of the feature 12.

[0148]

[0156] In operation 920, a chucking voltage is applied to the electrostatic chuck to clamp the substrate 10 to the electrostatic chuck. In some embodiments, the substrate 10 is positioned on the upper surface 792 of the electrostatic chuck 750, which supports and clamps the substrate 10 during processing. The electrostatic chuck 750 seals the substrate 10 to the upper surface 792 to prevent backside deposition. An electrical bias is supplied to the substrate 10 via a chucking electrode 810. The chucking electrode 810 may be in electrical communication with a chucking power supply 812, which provides a bias voltage to the chucking electrode 810. In some embodiments, the chucking voltage is between about 10 volts and about 9000 volts. In some embodiments, the chucking voltage is between about 100 volts and about 2000 volts. In some embodiments, the chucking voltage is between about 200 volts and about 1000 volts.

[0149]

[0157] In operation 920, several process parameters may be adjusted. In some embodiments suitable for processing 900 mm substrates, 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 900 mm substrates, the process temperature and / or substrate temperature may be maintained between −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.).

[0150]

[0158] In some embodiments, a constant chucking voltage is applied to the substrate 10. In some embodiments, the chucking voltage may be pulsed to the electrostatic chuck 750. In some embodiments, a backside gas may be applied to the substrate 10 while the chucking voltage is applied to control the temperature of the substrate. The backside gas may include, but is not limited to, helium (He), argon (Ar), etc.

[0151]

[0159] In operation 930, a plasma is generated at a horizontal surface of the substrate by applying a first RF bias to the electrostatic chuck. The plasma generated at the horizontal surface of the substrate may be generated in a plasma region between the substrate and the electrostatic chuck. The first RF bias may be 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) and at a power of about 10 Watts to about 9000 Watts. In some embodiments, the first RF bias is supplied at a frequency of about 13.56 MHz and at a power of about 2500 Watts to about 9000 Watts. In some embodiments, the first RF bias is supplied to the electrostatic chuck 750 via the second RF electrode 860. The second RF electrode 860 may be in electrical communication with a first RF power supply 830 that supplies a bias voltage to the second RF electrode 860. In some embodiments, the bias power is between about 10 Watts and about 9000 Watts. In some embodiments, the bias power is between about 2000 Watts and about 9000 Watts. In some embodiments, the bias power is between about 8500 Watts and about 9000 Watts. The first RF power source 830 may 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).

[0152]

[0160] In some embodiments, operation 930 further includes applying a second RF bias to the electrostatic chuck. The second RF bias can be between about 10 watts and about 9000 watts 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 some embodiments, the second RF bias is supplied at a frequency of about 2 MHz and at a power between about 800 watts and about 7200 watts. In some embodiments, the second RF bias is supplied to the substrate 10 via the chucking electrode 810. The chucking electrode 810 can be in electrical communication with a second RF power supply 840 that supplies a bias voltage to the chucking electrode 810. In some embodiments, the bias power is between about 10 watts and about 9000 watts. In some embodiments, the bias power is between about 500 watts and about 7500 watts. In some embodiments, the bias power is between about 800 Watts and about 7200 Watts. The second RF power source 840 may 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 some embodiments, the chucking voltage supplied during operation 920 is maintained during operation 930.

[0153]

[0161] In some embodiments, during operation 930, a first RF bias may be supplied to the substrate 10 via the chucking electrode 810 and a second RF bias may be supplied to the substrate 10 via the second RF electrode 860. In some embodiments, the first RF bias is about 8500 watts (13.56 MHz) and the second RF bias is about 1000 watts (2 MHz).

[0154]

[0162] During operation 940, a gap fill precursor is flowed into the processing space 726 to form a gap fill material in the substrate features. The gap fill precursor may be flowed into the processing space 726 from the gas panel 730, through the gas distribution assembly 720, or through the sidewall 701. In some embodiments, the gap fill precursor may further include an inert gas, a diluent gas, a nitrogen-containing gas, an etchant gas, or a combination thereof. In some embodiments, the gap fill precursor may include a hydrocarbon. In some embodiments, the gap fill precursor may include a silicon-containing species. The gap fill precursor may be any liquid or gas, although a preferred precursor is a room temperature vapor, as this simplifies the hardware required to meter, control, and deliver the material to the chamber. In some embodiments, the chucking voltage supplied during operation 920 is maintained during operation 940. In some embodiments, the process conditions established during operation 920 and the plasma formed during operation 930 are maintained during operation 940.

[0155]

[0163] In some embodiments, the hydrocarbon is gaseous. In some embodiments, the hydrocarbon is represented by the general formula C x H y where x ranges between 1 and 20 and y ranges between 1 and 26. Suitable hydrocarbons include, for example, C2H2, C3H6, CH4, C4H8, 1,3-dimethyladamantane, bicyclo[2.2.1]hepta-2,5-diene (2,5-norbornadiene), adamantane (C 10 H 16 ), norbornene (C7H 10 ), and combinations thereof. In one example, C2H2 is preferred because it forms a more stable intermediate species that allows for enhanced surface mobility.

[0156]

[0164] In some embodiments, the hydrocarbon compound is an alkane (e.g., C n H 2n+2 where n is between 1 and 20). Suitable hydrocarbons include alkanes (e.g., methane (CH), ethane (C), propane (C), butane (C), 10) and its isomers isobutane, pentane (CH 12 ), hexane (CH 14 ) and its isomers isopentane and neopentane, hexane (CH 14 ) and its isomers 2-methylpentane, 3-methylpentane, 2,3-dimethylbutane, and 2,2-dimethylbutane, or combinations thereof).

[0157]

[0165] In some embodiments, the hydrocarbon is an alkene (e.g., C n H 2n (where n is between 1 and 20). Suitable hydrocarbons include, for example, alkenes (e.g., acetylene, ethylene, propylene, butylene and its isomers, pentene and its isomers, etc.), dienes (e.g., butadiene, isoprene, pentadiene, hexadiene, or combinations thereof). Further suitable hydrocarbons include, for example, halogenated alkenes (e.g., monofluoroethylene, difluoroethylenes, trifluoroethylene, tetrafluoroethylene, monochloroethylene, dichloroethylenes, trichloroethylene, tetrachloroethylene, or combinations thereof).

[0158]

[0166] In some embodiments, the hydrocarbon compound is an alkyne (e.g., C n H -2n+2 where n is between 1 and 20. Suitable hydrocarbons include, for example, alkynes (e.g., acetylene (C2H4), propyne (C3H4), butylene (C4H8), vinylacetylene, or combinations thereof).

[0159]

[0167] In some embodiments, the hydrocarbon compound is an aromatic hydrocarbon (e.g., benzene, styrene, toluene, xylene, ethylbenzene, acetophenone, methyl benzoate, phenyl acetate, phenol, cresol, furan, etc.), α-terpinene, cymene, 1,1,3,3-tetramethylbutylbenzene, t-butyl ether, t-butyl ethylene, methyl methacrylate, and t-butyl furfuryl ether, compounds having the formulas CH and CH, halogenated aromatic compounds (including monofluorobenzene, difluorobenzene, tetrafluorobenzene, hexafluorobenzene, or combinations thereof).

[0160]

[0168] In some embodiments, the gap-filling precursor may comprise a silicon-containing species. Suitable silicon-containing species include species similar to the hydrocarbon materials provided above, but with silicon instead of carbon. For example, in some embodiments, the silicon-containing species is selected from silane, higher silane, cyclosilane, halosilane, and combinations thereof.

[0161]

[0169] In some embodiments, the gap-fill precursor further comprises one or more diluent gases. A suitable diluent gas (e.g., helium (He), argon (Ar), xenon (Xe), hydrogen (H), nitrogen (N), ammonia (NH), or a combination thereof, among others) may be added to the gas mixture if desired. Ar, He, and N can be used to control the density and deposition rate of the gap-fill material. In some embodiments, the addition of N and / or NH may be used to control the hydrogen ratio of the gap-fill material, as described below. Alternatively, no diluent gas may be used during deposition.

[0162]

[0170] In some embodiments, the gap-fill precursor further comprises one or more nitrogen-containing gases. Suitable nitrogen-containing gases include, for example, pyridine, aliphatic amines, amines, nitriles, ammonia, and similar compounds.

[0163]

[0171] In some embodiments, the gap-fill precursor further comprises an inert gas. In some embodiments, an inert gas (e.g., argon (Ar) and / or helium (He)) may be supplied into the process space 726 along with the gap-fill precursor. Other inert gases, such as nitrogen (N2) and nitric oxide (NO), may be used to control the density and deposition rate of the gap-fill material. Additionally, various other process gases may be added to the gap-fill precursor to modify the properties of the gap-fill material. In some embodiments, the other process gas may be a reactive gas, such as hydrogen (H2), ammonia (NH3), a mixture of hydrogen and nitrogen (H2), or a combination thereof. The addition of H2 and / or NH3 may be used to control the hydrogen ratio (e.g., carbon-to-hydrogen ratio) of the deposited gap-fill material. The ratio of hydrogen present in the diamond-like carbon material provides control over the layer properties (e.g., reflectivity).

[0164]

[0172] In some embodiments, the gap-fill precursor further comprises an etchant gas. Suitable etchant gases include chlorine (Cl), carbon tetrafluoride (CF), nitrogen trifluoride (NF), or combinations thereof. Without being bound by theory, it is believed that the etchant gas selectively etches sp hybridized carbon atoms from the film, thereby increasing the proportion of sp hybridized carbon atoms in the film.

[0165]

[0173] In some embodiments, the gap fill material 412 is exposed to hydrogen radicals after it is formed on the substrate during operation 940. In some embodiments, the gap fill material is exposed to hydrogen radicals during the deposition process of operation 940. In some embodiments, the hydrogen radicals are formed in the RPS and supplied to the processing region. Without being bound by theory, it is believed that exposing the gap fill material to hydrogen radicals results in selective etching of sp2 hybridized carbon atoms, thereby increasing the fraction of sp3 hybridized carbon atoms in the film.

[0166]

[0174] In operation 950, after the gap fill material 412 is formed on the substrate, the substrate is dechucking. In operation 950, the chucking voltage is turned off. The reactive gas is also turned off and optionally purged from the processing chamber. In some embodiments, the RF power is reduced (e.g., to 200 W) during operation 950. Optionally, the controller 710 monitors the change in impedance to determine whether the electrostatic charge has dissipated to ground through the RF path. Once the substrate is dechucking 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 transferred out of the chamber.

[0167]

[0175] In summary, some of the advantages of the present disclosure include providing a process for depositing gap fill materials in substrate features. In some embodiments described herein, low process pressures (mTorr vs. Torr) and bottom-driven plasmas enable the production of gap fill materials with approximately 60% or more sp3 hybridized atoms. Furthermore, some embodiments described herein are performed at low substrate temperatures, which enables the deposition of other dielectric films at temperatures much lower than those possible with current processes, opening up applications with low thermal budgets not currently addressable with CVD.

[0168]

[0176] When introducing elements of the disclosure or exemplary aspects or embodiments thereof, the articles "a," "an," "the," and "said" are intended to mean that there are one or more of the elements.

[0169]

[0177] The terms "comprising," "including," and "having" are intended to be inclusive and mean that there may be additional elements other than the listed elements.

[0170]

[0178] While the foregoing is directed to embodiments of the present disclosure, other and further embodiments of the disclosure may be devised without departing from the basic scope thereof, the scope of which is determined by the claims that follow.

[0171]

[0179] Throughout this specification, references to "one embodiment," "a particular embodiment," "one or more embodiments," or "an embodiment" mean that a particular feature, structure, material, or characteristic described in connection with that embodiment is included in at least one embodiment of the present disclosure. Thus, the appearances of the phrases "in one or more embodiments," "in a particular embodiment," "in one embodiment," or "in an embodiment" in various places throughout this specification are not necessarily all referring to the same embodiment of the present disclosure. Furthermore, particular features, structures, materials, or characteristics may be combined in any suitable manner in one or more embodiments.

[0172]

[0180] Although the present disclosure has been described with reference to particular embodiments, it is to be understood that these embodiments are merely illustrative of the principles and applications of the present disclosure. It will be apparent to those skilled in the art that various modifications and variations can be made in the disclosed method and apparatus without departing from the spirit and scope of the present disclosure. Therefore, it is intended that the present disclosure cover modifications and variations that come within the scope of the appended claims and their equivalents.

Claims

1. 1. A method of gap-fill deposition comprising the steps of: generating a plasma from a gap-fill material precursor above the substrate by simultaneously applying a first RF bias and a second RF bias to an electrostatic chuck supporting the substrate, and depositing gap-fill material in at least one feature in the substrate, the at least one feature extending a depth from a substrate surface to a bottom surface, the at least one feature having an opening width at the substrate surface defined by a first sidewall and a second sidewall; 23. A method of depositing a gap fill material comprising:

2. The method of claim 1, wherein the gap filling material is substantially free of voids.

3. The method of claim 1, wherein the substrate is maintained at a temperature of about 10°C to about 100°C.

4. The method of claim 1, wherein at least one feature has a ratio of the depth to the opening width of about 5:1 or greater.

5. The method of claim 1, wherein the gap filler precursor comprises a silicon-containing species and the gap filler comprises a dielectric material.

6. The method of claim 5, wherein the dielectric material comprises one or more of silicon, silicon oxide, or silicon nitride.

7. The method of claim 1, wherein the gap filler precursor comprises a hydrocarbon and the gap filler comprises a diamond-like carbon material.

8. The method of claim 7, wherein the hydrocarbon is selected from the group consisting of C2H2, C3H6, CH4, C4H8, 1,3-dimethyladamantane, bicyclo[2.2.1]hepta-2,5-diene (2,5-norbornadiene), adamantane (C10H16), norbornene (C7H10), and combinations thereof.

9. A diamond-like carbon gap filler in a feature of a substrate provided by the method of claim 7.

10. The diamond-like carbon gap filler of claim 9, wherein the gap filler has a density greater than 1.5 g / cm3, a stress less than 100 MPa, a refractive index greater than 2.0, an extinction coefficient or k value (K (at 633 nm)) greater than 0.1, or at least 40% sp3 hybridized carbon atoms.

11. A method for depositing a gap-filling material, comprising the steps of: flowing a gap-fill precursor into a processing space of a processing chamber, the processing space including a substrate positioned on a first electrode, the substrate having a substrate surface with at least one feature therein, the at least one feature extending a depth from the substrate surface to a bottom surface, the at least one feature having an opening width at the substrate surface defined by a first sidewall and a second sidewall, the processing chamber further including a second electrode positioned above the first electrode and the substrate, the second electrode having a surface including a secondary electrode emission material comprising one or more of a silicon-containing material or a carbon-containing material; applying a first RF power to at least one of the first electrode and the second electrode; forming a gap fill material within the at least one feature of the substrate; 23. A method of depositing a gap fill material comprising:

12. The method of claim 11, wherein the first RF power is applied to the first electrode and no power is supplied to the second electrode.

13. The method of claim 11, wherein the first RF power is applied to the second electrode and no power is supplied to the first electrode.

14. The method of claim 11, wherein the first RF power is applied to both the first electrode and the second electrode.

15. The method of claim 11, wherein the gap filling material is substantially free of voids.

16. The method described in claim 11, wherein at least one of the features has a ratio of the depth to the opening width of about 5:1 or greater.

17. The method of claim 17, wherein the gap filler comprises a dielectric material comprising one or more of silicon, silicon oxide, or silicon nitride; and The method of claim 11 , wherein the gap-fill precursor comprises a silicon-containing species or the secondary electrode emission material comprises a silicon-containing material.

18. The method of claim 17, wherein the gap filling material comprises a diamond-like carbon material; and The method of claim 11 , wherein the gap fill precursor comprises a hydrocarbon or the secondary electrode emission material comprises a carbon-containing material.

19. A diamond-like carbon gap filler in a feature of a substrate provided by the method of claim 18.

20. The diamond-like carbon gap filler of claim 19, wherein the gap filler has a density greater than 1.5 g / cm3, a stress less than 100 MPa, a refractive index greater than 2.0, an extinction coefficient or k value (K (at 633 nm)) greater than 0.1, or at least 40% sp3 hybridized carbon atoms.

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