Systems and methods for depositing low-κ dielectric films

Abstract

Embodiments of a semiconductor processing method for forming a low-κ film on a semiconductor substrate are described. The processing method can include flowing a deposition precursor into a substrate processing region of a semiconductor processing chamber. The deposition precursor can include a silicon-containing precursor having at least one vinyl group. The method can further include generating a deposition plasma from the deposition precursor in the substrate processing region. A silicon-carbon-containing material characterized by a dielectric constant (κ value) of about 3.0 or less can be deposited on the substrate from plasma effluents of the deposition plasma.

Description

[Technical Field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of and priority to U.S. Non-Provisional Application No. 17 / 021,035, filed September 15, 2020, and entitled "SYSTEMS AND METHODS FOR DEPOSITING LOW-K DIELECTRIC FILMS," the contents of which are incorporated herein by reference in their entirety for all purposes. Technical Field

[0002] The present technology relates to deposition processes and chambers, and more particularly to methods for producing low-κ films that may not utilize UV treatment. [Background technology]

[0002] background

[0003] Integrated circuits are made possible by processes that create intricately patterned layers of material on substrate surfaces. Fabricating patterned materials on substrates requires controlled methods for forming and removing materials. The properties of the materials can affect how the device operates and can also affect how films are removed relative to one another. Plasma-enhanced deposition can produce films with specific characteristics. Many films that are formed require additional processing to tailor or enhance the material properties of the film to provide the appropriate properties.

[0003]

[0004] Therefore, there is a need for improved systems and methods that can be used to manufacture high quality devices and structures. These and other needs are addressed by current technology. Summary of the Invention

[0004]

[0005] Embodiments of the present technology include semiconductor processing methods for forming dielectric films with a low dielectric constant (i.e., low-κ) compared to silicon dioxide (κ=3.9). Dielectric film embodiments include carbon-containing silicon oxide films with a dielectric constant (i.e., κ value) of 3.0 or less. In processing method embodiments, these low-κ carbon-containing dielectric films can be formed as electrically insulating dielectric layers between metal lines and contacts in back-end-of-line (BEOL) semiconductor manufacturing processes. The low κ values of these carbon-containing silicon oxide films may reduce RC delays, crosstalk noise, and power losses in signal propagation across metal lines and contacts separated by the low-κ film.

[0005]

[0006] Embodiments of semiconductor processing methods can include flowing a deposition precursor into a substrate processing region of a semiconductor processing chamber. The deposition precursor can include a silicon-containing precursor having at least one vinyl group. These methods can further include generating a deposition plasma in the substrate processing region from the deposition precursor. Silicon- and carbon-containing materials characterized by a dielectric constant (κ value) of about 3.0 or less can be deposited on a substrate from the plasma flow of the deposition plasma.

[0006]

[0007] In additional embodiments, the silicon-containing precursor is represented by Formula 1: TIFF0007723734000001.tif34170 (wherein R1, R2, and R3 may contain a C1 to C6 alkyl group or a C1 to C6 alkoxy group, and at least one of R1, R2, and R3 is an alkoxy group, and at least one of R1, R2, and R3 is an alkoxy group.) can be characterized by

[0007]

[0008] In further embodiments, the silicon-containing precursor may include vinylmethyldimethoxysilane. In some embodiments, the deposition precursor may further include molecular oxygen. In embodiments, the flow ratio of molecular oxygen to the silicon-containing precursor may be about 2:1 or greater. In further embodiments, the silicon- and carbon-containing material may be characterized by methyl incorporation greater than 2.5 atomic %. In yet another embodiment, the silicon- and carbon-containing material may be characterized by a Young's modulus of about 5 GPa or greater. In yet another embodiment, the silicon- and carbon-containing material may be characterized by a hardness of about 3 GPa or greater.

[0008]

[0009] Embodiments of the present technology may include additional methods for forming low-κ dielectric films. Method embodiments may include flowing a deposition precursor into a substrate processing region of a semiconductor processing chamber. In embodiments, the deposition precursor may include a silicon-carbon and oxygen-containing precursor. Method embodiments may further include generating a deposition plasma from the deposition precursor in the substrate processing region. The semiconductor processing chamber may be characterized by a temperature of about 400° C. or greater during generation of the deposition plasma. Plasma effluents from the deposition plasma may deposit a silicon-carbon and oxygen-containing material on the substrate. In some embodiments, the as-deposited silicon-carbon and oxygen-containing material may be characterized by a dielectric constant (κ value) of about 3.0 or less.

[0009]

[0010] In additional embodiments, the semiconductor processing chamber may be characterized by a temperature of about 420° C. or greater during generation of the deposition plasma. In further embodiments, the deposition precursor may further include molecular oxygen (O), and the molecular oxygen may be characterized by a flow rate of less than about 150 sccm into the semiconductor processing chamber. In further embodiments, the silicon-carbon and oxygen-containing precursor may include at least one vinyl group. In yet additional embodiments, the as-deposited silicon-carbon and oxygen-containing material may be characterized by a carbon content of about 25 atomic % or greater. In yet additional embodiments, the silicon-carbon and oxygen-containing material may be characterized by a Young's modulus of about 5 GPa or greater and may be further characterized by a hardness of about 3 GPa or greater.

[0010]

[0011] Embodiments of the present technology may include yet another method for forming a low-κ dielectric film. The method may include flowing a deposition precursor into a substrate processing region of a semiconductor processing chamber. The deposition precursor may include a silicon-containing precursor and molecular oxygen (O). In some embodiments, the silicon-containing precursor may be characterized by a flow rate of about 2000 mgm or less into the semiconductor processing chamber, and the O may be characterized by a flow rate of about 120 sccm or less. The method may further include generating a deposition plasma from the deposition precursor in the substrate processing region. The method may further include depositing a silicon-carbon and oxygen-containing material on the substrate from the plasma flow of the deposition plasma. In some embodiments, the as-deposited silicon-carbon and oxygen-containing material may be characterized by a dielectric constant of about 3.0 or less.

[0011]

[0012] In additional embodiments, the flow ratio of molecular oxygen to the silicon-containing precursor can be about 2:1 or greater. In further embodiments, the deposition precursor can further include at least one carrier gas. In some embodiments, the carrier gas can include at least one of helium or nitrogen (N2). In yet additional embodiments, the as-deposited silicon-carbon and oxygen-containing material can be characterized by a methyl incorporation greater than 2.5 atomic % and a carbon content greater than about 25 atomic %. In yet additional embodiments, the silicon-carbon and oxygen-containing material can be characterized by a Young's modulus of about 5 GPa or greater and can be further characterized by a hardness of about 3 GPa or greater.

[0012]

[0013] Such techniques may offer numerous advantages over conventional processing methods. For example, utilizing silicon-containing precursors containing organic moieties with unsaturated carbon-carbon bonds, such as moieties containing vinyl groups, can increase the Si-C crosslinking of as-deposited low-κ materials. This increased amount of Si-C crosslinking allows for increased carbon levels in the materials without reducing mechanical properties such as Young's modulus and hardness. Increasing the carbon level in these low-κ films reduces the dielectric constant (κ value) of the films to approximately 3.0 or less without simultaneously reducing the mechanical stability of the films. Embodiments of the present technology also include processing methods in which the deposition of low-κ materials can be carried out at temperatures of 420°C or higher. Increasing the deposition temperature also increases the amount of Si-C crosslinking in the low-κ materials. Furthermore, embodiments of the present technology may include deposition precursors that combine a silicon-containing precursor with molecular oxygen delivered to a semiconductor processing chamber at a flow rate of approximately 120 sccm or higher. Increasing the oxygen flow rate may also increase the Si-C and Si-O crosslinking of the low-κ materials by reducing the amount of methyl groups incorporated into the as-deposited materials. In yet further embodiments of the present technology, the as-deposited low-κ materials can be characterized by low κ values and high mechanical stability without undergoing post-deposition UV treatments that add additional time and complexity to the processing method. These and other embodiments, along with many of their advantages and features, are described in more detail in conjunction with the following description and accompanying figures.

[0013]

[0014] A further understanding of the nature and advantages of the disclosed technology may be realized by reference to the remaining portions of the specification and drawings. [Brief explanation of the drawings]

[0014] [Figure 1]

[0015] 1 illustrates a top view of an exemplary processing system in accordance with some embodiments of the present technique. [Figure 2]

[0016] 1 shows a schematic cross-sectional view of an exemplary plasma system in accordance with some embodiments of the present technique; [Figure 3]

[0017] 1 illustrates operations of an exemplary method of semiconductor processing in accordance with some embodiments of the present technique. DETAILED DESCRIPTION OF THE INVENTION

[0015]

[0018] Some of the figures are included as circuit diagrams. It should be understood that these figures are for illustrative purposes and should not be considered to scale unless specifically stated to be to scale. Furthermore, as schematic diagrams, the figures are provided to aid in understanding and may not include all aspects or information compared to realistic representations and may include exaggerated material for illustrative purposes.

[0016]

[0019] In the accompanying figures, similar components and / or features may have the same reference label. Furthermore, various components of the same type may be distinguished by tracing the reference numerals with a letter that distinguishes between the similar components. When only a first reference numeral is used herein, the description is applicable to any one of the similar components having the same first reference numeral, regardless of the letter.

[0017]

[0020] In back-end-of-line (BEOL) semiconductor processing, low-κ films can serve multiple functions in the fabrication of metallization layers in integrated circuits. These functions can include the incorporation of electrically insulating low-κ films between conductive metal-containing structures such as interconnect lines, contact holes, and vias, among other structures. They can also include the partial removal of low-κ films following the formation of metal structures. One common removal process in BEOL processing is chemical-mechanical polishing (CMP), which combines chemical etching and physical polishing to remove low-κ materials from the substrate surface.

[0018]

[0021] Low-κ films used in BEOL processes must have a low dielectric constant (κ value) compared to undoped silicon oxide and high mechanical stability to resist spalling during the formation of metal-containing structures and removal by CMP. Unfortunately, these qualities are often in tension in low-κ films made from silicon-carbon and oxygen-containing materials. Often, a high carbon content in the material can reduce the κ value and the film's mechanical stability, among other mechanical properties of the film, as characterized by a lower Young's modulus and lower hardness.

[0019]

[0022] One approach to improving the mechanical stability of low-κ films is to treat the as-deposited films with ultraviolet light (i.e., UV treatment / curing operations). Unfortunately, these UV treatment operations often involve transferring the substrate from the low-κ film deposition chamber to a UV treatment chamber, adding time and complexity to the overall low-κ film deposition operation. UV light often penetrates low-κ materials only to a depth of a few angstroms, and a fully processed low-κ film requires several shuttles of the substrate between the deposition and treatment chambers to achieve a low-κ film thickness of tens to hundreds of angstroms. Multiple deposition and treatment operations can significantly reduce wafer throughput in semiconductor manufacturing processes.

[0020]

[0023] The present technology overcomes these problems by including embodiments of semiconductor processing methods that form low-κ films with good mechanical stability. In embodiments, these low-κ films can be characterized by a high Young's modulus (e.g., about 5 GPa or greater) and high hardness (e.g., about 3 GPa or greater). Deposition at high temperatures using specific precursors characterized by specific oxygen-to-carbon ratios can increase silicon-carbon bridges and silicon-oxide bonds within the low-κ films while maintaining the carbon fraction necessary to maintain a reduced dielectric constant. This can overcome the natural tendency for modulus, hardness, and other properties of the film's mechanical stability to decrease as the dielectric constant decreases, while also reducing the number of operations required during processing. Notably, the present technology does not require subsequent post-deposition treatments, including UV exposure, plasma treatment, or other processing operations, to post-treat the film to improve hardness.

[0021]

[0024] While the remainder of the disclosure routinely identifies particular deposition processes utilizing the disclosed technology, it will be readily understood that the systems and methods are equally applicable to other deposition and cleaning chambers and processes that may occur in the described chambers. Thus, the technology should not be considered limited for use with only these particular deposition processes or chambers. This disclosure will discuss one possible system and chamber that may be used to perform a deposition process in accordance with embodiments of the present technology before describing additional details in accordance with embodiments of the present technology.

[0022]

[0025] FIG. 1 illustrates a top view of one embodiment of a deposition, etch, bake, and cure chamber processing system 100, according to an embodiment. In the figure, a pair of front-opening integrated pods 102 deliver substrates of various sizes that are received by a robotic arm 104, placed in one of the substrate processing chambers 108a-f, and placed in a low-pressure holding area 106 before being positioned in tandem sections 109a-c. A second robotic arm 110 can be used to transfer substrate wafers from the holding area 106 to and from the substrate processing chambers 108a-f. Each substrate processing chamber 108a-f can be equipped to perform multiple substrate processing operations, including plasma-enhanced chemical vapor deposition, atomic layer deposition, physical vapor deposition, etching, pre-cleaning, degassing, alignment, and other substrate processes, including annealing, ashing, and the like.

[0023]

[0026] The substrate processing chambers 108a-f can include one or more system components for depositing, annealing, curing, and / or etching a dielectric or other film on a substrate. In one configuration, two pairs of processing chambers, e.g., 108c-d and 108e-f, can be used to deposit a dielectric material on a substrate, and a third pair of processing chambers, e.g., 108a-b, can be used to etch the deposited dielectric. In another configuration, all three pairs of chambers, e.g., 108a-f, can be configured to deposit a stack of alternating dielectric films on a substrate. Any one or more of the described processes can be performed in chambers separate from the fabrication system shown in different embodiments. It should be understood that additional configurations of deposition, etching, annealing, and curing chambers for dielectric films are contemplated by system 100.

[0024]

[0027] 2 shows a schematic cross-sectional view of an exemplary plasma system 200 in accordance with some embodiments of the present technique. The plasma system 200 may show a pair of processing chambers 108 that may fit into one or more of the tandem sections 109 described above, which may include lid stack components in accordance with embodiments of the present technique, and may be further described below. The plasma system 200 may generally include a chamber body 202 having a sidewall 212, a bottom wall 216, and an interior sidewall 201 that define a pair of processing regions 220A and 220B. Each of the processing regions 220A-220B may be similarly configured and may include identical components.

[0025]

[0028] For example, processing region 220B, whose components may be included in processing region 220A, may include a pedestal 228 disposed in the processing region through a passageway 222 formed in the bottom wall 216 of the plasma system 200. The pedestal 228 may provide a heater adapted to support a substrate 229 on an exposed surface of the pedestal, such as a body portion. The pedestal 228 may include a heating element 232, such as a resistive heating element, that may heat and control the substrate temperature at a desired processing temperature. The pedestal 228 may also be heated by a remote heating element, such as a lamp assembly, or any other heating device.

[0026]

[0029] The body of the pedestal 228 can be coupled to the stem 226 by a flange 233. The stem 226 can electrically couple the pedestal 228 to a power outlet or power box 203. The power box 203 can include a drive system that controls the elevation and movement of the pedestal 228 within the processing region 220B. The stem 226 can also include a power interface for supplying power to the pedestal 228. The power box 203 can also include an interface for power and temperature indicators, such as a thermocouple interface. The stem 226 can include a base assembly 238 adapted to removably couple with the power box 203. A circumferential ring 235 is shown on the power box 203. In some embodiments, the circumferential ring 235 can be a shoulder adapted as a mechanical stop or land configured to provide a mechanical interface between the base assembly 238 and the top surface of the power box 203.

[0027]

[0030] The rod 230 may be contained through a passage 224 formed in the bottom wall 216 of the processing region 220B and may also be utilized to position substrate lift pins 261 disposed through the body of the pedestal 228. The substrate lift pins 261 may selectively move the substrate 229 away from the pedestal to facilitate exchange of the substrate 229 with a robot utilized to move the substrate 229 into and out of the processing region 220B through the substrate transfer port 260.

[0028]

[0031] A chamber lid 204 may be coupled to the top of the chamber body 202. The lid 204 may house one or more precursor delivery systems 208 coupled thereto. The precursor delivery system 208 may include a precursor inlet passage 240 that may deliver reactant and cleaning precursors into the processing region 220B via a dual channel showerhead 218. The dual channel showerhead 218 may include an annular base plate 248 having a blocker plate 244 disposed intermediate a faceplate 246. A radio frequency (“RF”) source 265 may be coupled to the dual channel showerhead 218, which may provide power to the dual channel showerhead 218 to facilitate generation of a plasma region between the faceplate 246 and the pedestal 228 of the dual channel showerhead 218. The dual channel showerhead 218 and / or the faceplate 246 may include one or more openings that allow precursors to flow from the precursor delivery system 208 to the processing region 220A and / or 220B. In some embodiments, the opening may include at least one of a linear opening and a conical opening. In some embodiments, the RF source may be coupled to other portions of the chamber body 202, such as the pedestal 228, to facilitate plasma generation. A dielectric isolator 258 may be disposed between the lid 204 and the dual-channel showerhead 218 to prevent RF power from being conducted to the lid 204. A shadow ring 206 may be disposed around the pedestal 228 to engage the pedestal 228.

[0029]

[0032] Optional cooling channels 247 can be formed in the annular base plate 248 of the precursor delivery system 208 to cool the annular base plate 248 during operation. A heat transfer fluid, such as water, ethylene glycol, or gas, can be circulated through the cooling channels 247 to maintain the base plate 248 at a predetermined temperature. A liner assembly 227 can be positioned within the processing region 220B in close proximity to the sidewalls 201, 212 of the chamber body 202 to prevent exposure of the sidewalls 201, 212 to the processing environment within the processing region 220B. The liner assembly 227 can include a circumferential pumping cavity 225 that can be coupled to a pumping system 264 configured to evacuate gases and byproducts from the processing region 220B and control the pressure within the processing region 220B. A plurality of exhaust ports 231 can be formed on the liner assembly 227. The exhaust ports 231 can be configured to allow gas flow from the processing region 220B to the circumferential pumping cavity 225 in a manner that facilitates processing within the system 200.

[0030]

[0033] 3 illustrates operations of an exemplary method 300 of semiconductor processing in accordance with some embodiments of the present technique. The method may be performed in a variety of processing chambers, including the processing system 200 described above, as well as any other chamber in which plasma deposition may be performed. Method 300 may include several optional operations that may or may not be specifically associated with some embodiments of the method in accordance with the present technique.

[0031]

[0034] Method 300 can include a plasma-enhanced chemical vapor deposition (PECVD) processing operation to form as-deposited, low-κ films with high mechanical stability. In contrast to conventional methods, these as-deposited, low-κ films do not require post-deposition treatments, such as UV curing, to enhance the film's mechanical stability. In some embodiments, the method can include optional operations before the start of method 300, or the method can include additional operations after deposition of the mechanically stable low-κ material. In additional embodiments, method 300 can include flowing a deposition precursor into a substrate processing region of a semiconductor processing chamber, as shown in FIG. 3 , in operation 305. In embodiments, a substrate can be present in the substrate processing region of the semiconductor processing chamber when the deposition precursor flows into the chamber.

[0032]

[0035] In some embodiments, the deposition precursor can include a silicon-containing precursor having at least one vinyl group (i.e., a -CH=CH group). In additional embodiments, the silicon-containing precursor can have at least two vinyl groups. In yet additional embodiments, the silicon-containing precursor can be represented by Formula 1: TIFF0007723734000002.tif35170 (wherein R1, R2, and R3 may contain a C1 to C6 alkyl group or a C1 to C6 alkoxy group, and at least one of R1, R2, and R3 is an alkoxy group, and at least one of R1, R2, and R3 is an alkoxy group.) In a further embodiment, the silicon-containing precursor may be a vinyl group-containing vinylmethyldimethoxysilane, which may be represented by the following structural formula: TIFF0007723734000003.tif43170Vinylmethyldimethoxysilane

[0033]

[0036] In further embodiments, the silicon-containing precursor can include precursors having Si—O and Si—C bonds, and can include linear, branched, cyclic, or any number of additional silicon-containing precursors. In some embodiments, the silicon-containing precursor can be characterized by a specific molar ratio of carbon and / or oxygen to silicon. For example, in some embodiments, the ratio of carbon or oxygen to silicon can be about 1 or greater, or about 1.5 or greater, about 2 or greater, about 2.5 or greater, about 3 or greater, about 3.5 or greater, about 4 or greater, or greater. Increasing the amount of carbon or oxygen relative to silicon can increase the incorporation of additional residual moieties or molecules into the film. This can improve material properties as well as lower the dielectric constant, as discussed further below.

[0034]

[0037] In further embodiments, the silicon-containing precursor can include a silicon-oxygen and carbon-containing precursor. In embodiments, the silicon-oxygen and carbon-containing precursor can be characterized by a carbon-to-oxygen ratio of about 4:1 or less, about 3:1 or less, about 2:1 or less, about 4:3 or less, or less. In embodiments, increasing the amount of oxygen in the as-deposited low-κ film provided by the silicon-oxygen and carbon-containing precursor can increase the mechanical stability of the film. In additional embodiments, the amount of oxygen provided by the silicon-oxygen and carbon-containing precursor can be balanced against the amount of carbon in the low-κ film to maintain a low value of the film's dielectric constant (κ value).

[0035]

[0038] In additional embodiments, the silicon-containing precursor may include a silicon-oxygen and carbon-containing precursor having a central silicon atom and at least one methyl group and at least one methoxy group bonded to the central silicon. In embodiments, these methyl-methoxysiloxane precursors may include DMDMOS, TMMOS, and MTMOS. In further embodiments, the silicon-containing precursor may include at least one silicon atom, at least one silicon-to-alkyl group bond, and at least one silicon-to-alkoxy group bond. In additional embodiments, the silicon-containing precursor may include a single silicon atom and an alkyl group and an alkoxy group both bonded to the silicon atom. In yet further embodiments, the silicon-containing precursor may include two or more silicon atoms. In further embodiments, the silicon-containing precursor may have an alkyl group, such as ethyl, propyl, butyl, pentyl, and / or hexyl, in addition to or in place of one or more methyl groups. In further embodiments, the silicon-containing precursor may have alkoxy groups, such as ethoxy, propoxy, butoxy, pentoxy, and / or hexoxy groups, in addition to or in place of one or more methoxy groups. In embodiments, the silicon-containing precursor may include one or more of dimethyldimethoxysilane, bis(methyldimethoxysilyl)methane, methyltrimethoxysilane, isobutylmethyldimethoxysilane, tetramethyl-1,3-dimethoxydisiloxane, trimethylmethoxysilane, diethoxymethylsilane, octamethoxycyclotetrasiloxane, isobutyltrimethoxysilane, 1,3-dimethyl-1,1,3,3-tetramethoxydisiloxane, 1,2-bis(methyldimethoxysilyl)ethane, propylmethyldimethoxysilane, and 1,3,5,7-tetramethyl-1,3,5,7-tetramethoxycyclotetrasiloxane.

[0036]

[0039] Additional embodiments of silicon-containing precursors are represented by Formula 2: TIFF0007723734000004.tif34170Equation 2 R 1comprises a C1-C6 alkyl group such as -CH3, -CH2CH3, -CH2CH2CH3, -CH2CH2CH2CH3, -CH2CH2CH2CH2CH3, or -CH2CH2CH2CH2CH2CH2CH3; R 2 comprises a C1-C6 alkyl group such as -CH3, -CH2CH3, -CH2CH2CH3, -CH2CH2CH2CH3, -CH2CH2CH2CH2CH3, or -CH2CH2CH2CH2CH2CH2CH3; R 3 are -OCH3, -CH3, -H, -(CH2) n CH3, -O(CH2) n CH3, -CH=CH2, -CH2-CH2-(CH2CH3)2, or -CH2-CH(CH3)2, where n=1 to 5; R 4 are -OCH3, -CH3, -H, -(CH2) n CH3, -O(CH2) n It includes CH3, -CH=CH2, -CH2-CH2-(CH2CH3)2, or -CH2-CH(CH3)2, where n=1 to 5.

[0037]

[0040] In some embodiments, the deposition precursor can further include molecular oxygen (O). In embodiments, the flow rate of O relative to the flow rate of the silicon-containing precursor can be maintained at a flow rate ratio that supports the formation of as-deposited low-κ films with both a low dielectric constant (κ value) and high mechanical stability, particularly as reflected in film properties such as Young's modulus and hardness. In embodiments, the flow rate ratio of O relative to the silicon-containing precursor can be about 2:1 or greater, about 2.5:1 or greater, about 3:1 or greater, about 3.5:1 or greater, about 4:1 or greater, about 4.5:1 or greater, about 5:1 or greater, or greater.

[0038]

[0041] In further embodiments, the deposition precursors may also include one or more carrier gases, such as helium and nitrogen (N2). Although one or more carrier gases may be supplied along with the other deposition precursors, the carrier gases may be considered inert gases that do not react to form part of the as-deposited low-κ film.

[0039]

[0042] In additional embodiments, the flow rate of the silicon-containing precursor can be about 2000 milligrams per minute (mgm) or greater, about 2100 mgm or greater, about 2250 mgm or greater, about 2500 mgm or greater, about 2750 mgm or greater, about 2900 mgm or greater, about 3000 mgm or greater, or greater. In further embodiments, the flow rate of O can be about 120 sccm or greater, about 130 sccm or greater, about 140 sccm or greater, about 150 sccm or greater, about 200 sccm or greater, about 250 sccm or greater, about 300 sccm or greater, about 350 sccm or greater, about 400 sccm or greater, about 450 sccm or greater, about 500 sccm or greater, or greater. In still further embodiments, the flow rate of one or more carrier gases can be 1000 sccm or greater, 2000 sccm or greater, 3000 sccm or greater, 3000 sccm or greater, 4000 sccm or greater, 5000 sccm or greater, or greater. In still further embodiments, the flow rate of the combined deposition precursors can be 1150 sccm or greater, about 1500 sccm or greater, about 2000 sccm or greater, about 3000 sccm or greater, about 4000 sccm or greater, about 5000 sccm or greater, or greater.

[0040]

[0043] In some embodiments, it has been observed that excessive O flow rates relative to silicon-containing precursors can result in abnormally large dielectric constants for as-deposited low-κ films. It is believed that excessive O flow rates in these instances can increase the number of reactions between oxygen and hydrogen in the film, generating hydroxyl (—OH) groups. In many embodiments, the dielectric constant of low-κ films containing silicon, oxygen, and carbon can be very sensitive to the amount of hydroxyl groups in the film. A relatively small increase in the amount of hydroxyl groups in the film (e.g., an increase of about 1 atomic % or less) can cause a relatively large increase in the film's dielectric constant (e.g., an increase of about 10% or more). In some embodiments, the O flow rate can be about 200 sccm or less, about 180 sccm or less, about 160 sccm or less, about 150 sccm or less, or even lower.

[0041]

[0044] In additional embodiments, deposition precursors flowed into the substrate processing region of the semiconductor processing chamber can change the pressure within the chamber. In embodiments, during formation of low-κ films, the semiconductor substrate chamber pressure can be characterized by a pressure of about 1 Torr or greater, about 2 Torr or greater, about 3 Torr or greater, about 4 Torr or greater, about 5 Torr or greater, about 6 Torr or greater, about 7 Torr or greater, about 8 Torr or greater, about 9 Torr or greater, about 10 Torr or greater, or greater.

[0042]

[0045] Embodiments of method 300 may further include generating a deposition plasma from the deposition precursor in operation 310. In embodiments, the deposition plasma may be generated from the deposition precursor within a processing region of the semiconductor processing chamber, such as by supplying RF power to a faceplate to generate a plasma within the substrate processing region. The deposition plasma may be generated at any of the frequencies described above, and may be generated at a frequency less than 15 MHz (e.g., 13.56 MHz). Although higher frequencies may be used, in some embodiments, lower frequency plasma generation may facilitate carbon removal during processing, as opposed to higher plasma frequency operation.

[0043]

[0046] Embodiments of method 300 may further include depositing a low-κ film on a substrate in operation 315. In embodiments, the substrate is present in a substrate processing region of a semiconductor processing chamber, and the low-κ film is formed from deposition plasma effluents generated by a deposition plasma also present in the processing region. In some embodiments, during deposition, the substrate can be characterized by a temperature of 400°C or greater, about 405°C or greater, about 410°C or greater, about 415°C or greater, about 420°C or greater, about 425°C or greater, about 430°C or greater, about 435°C or greater, about 440°C or greater, about 445°C or greater, about 450°C or greater, or greater. In embodiments, the substrate temperature can be set to increase the amount of Si-C crosslinking in the as-deposited low-κ film. The increased Si-C crosslinking can enhance the mechanical stability of the low-κ film. In embodiments, the as-deposited low-κ film can be characterized by an increased Young's modulus and increased hardness at elevated temperatures. On the other hand, excessively high temperatures can volatilize carbon in the low-κ film during deposition, causing it to outgas. At excessively high temperatures, significant amounts of carbon can be removed from the low-κ film as carbon oxides (e.g., CO, CO) and volatile organic compounds (e.g., —CH, CH), reducing the carbon level in the film. The reduced carbon level can increase the dielectric constant (κ value) of the film to levels of 3.0 or greater, about 3.1 or greater, about 3.2 or greater, about 3.3 or greater, about 3.4 or greater, about 3.5 or greater, or even higher. In some embodiments, the substrate during deposition of the low-κ film can be characterized by a temperature of about 450° C. or less.

[0044]

[0047] In some embodiments, the deposition rate of low-κ films can exceed 500 Å / min, and can be deposited at rates of about 700 Å / min or greater, about 1,000 Å / min or greater, about 1,200 Å / min or greater, about 1,400 Å / min or greater, about 1,600 Å / min or greater, about 1,800 Å / min or greater, or about 2,000 Å / min or greater. After deposition to a sufficient thickness (e.g., less than about 1,000 Å), many conventional processes then transfer the substrate to a second chamber to perform treatments such as UV treatments or other post-deposition treatments. This can reduce throughput and increase production costs due to the need for additional chambers or tools to perform the treatments. However, the present technique can produce materials including carbon-doped silicon oxide that can be characterized by sufficient material properties as deposited without additional treatments such as UV treatments. While embodiments of the present technique can include additional post-deposition treatments, the as-deposited properties of the films can include a range of improvements over conventional techniques.

[0045]

[0048] As described above, the processing methods of the present technology include embodiments that utilize deposition precursors and processing conditions that form low-κ films with low dielectric constants and high mechanical stability. In embodiments of processing method 300, the as-deposited low-κ films can be formed as silicon-carbon and oxygen-containing films with dielectric constants of about 3.0 or less, about 2.9 or less, about 2.8 or less, about 2.7 or less, about 2.6 or less, or less. The low dielectric constant of the films can be at least partially attributed to the amount of carbon in the films. In embodiments, the amount of carbon, as an atomic percentage, in the as-deposited low-κ films can be about 25 atomic % or more, about 26 atomic % or more, about 27 atomic % or more, about 28 atomic % or more, about 29 atomic % or more, about 30 atomic % or more, or more.

[0046]

[0049] Low-κ films containing about 25 atomic % or more carbon typically have poor mechanical stability when formed by conventional deposition methods. The processing methods of the present technology include embodiments that produce as-deposited low-κ films characterized by high mechanical stability at high carbon levels. In embodiments, the as-deposited low-κ films can be characterized by a Young's modulus of about 5 GPa or greater, and can be characterized by a Young's modulus of about 7.5 GPa or greater, about 10 GPa or greater, about 15 GPa or greater to about 16 GPa or greater, about 17 GPa or greater, about 18 GPa or greater, about 19 GPa or greater, about 20 GPa or greater, or greater. In further embodiments, the as-deposited low-κ films can be characterized by a hardness of about 3 GPa or greater, about 3.5 GPa or greater, about 4 GPa or greater, about 4.5 GPa or greater, about 5 GPa or greater, about 5.5 GPa or greater, about 6 GPa or greater, about 6.5 GPa or greater, about 7 GPa or greater, about 7.5 GPa or greater, about 8 GPa or greater, about 10 GPa or greater, or more.

[0047]

[0050] In some embodiments, the reduced dielectric constant (κ value) and improved mechanical stability of low-κ films may be correlated with an increased level of methyl groups as a fraction of the total carbon in the films. In embodiments, the increased level of methyl groups may be due in part to silicon-containing deposition precursors that also contain at least one vinyl group. Vinyl groups are readily hydrogenated to form methyl groups at deposition temperatures. As-deposited low-κ films can be characterized by the percentage of methyl group (—CH3) atoms (i.e., molecules) relative to the silicon oxide (SiO) groups of the low-κ film, as measured by the area of the infrared absorption peak attributed to these groups. In embodiments, the atomic percentage of methyl groups (—CH3) can be 2.5 atomic % or greater, 2.75 atomic % or greater, greater than about 3 atomic %, 3.25 atomic % or greater, 3.75 atomic % or greater, 4 atomic % or greater, or even greater.

[0048]

[0051] As discussed above, the ability of embodiments of the present technology to form low-κ films with low dielectric constants and high mechanical stability can be attributed, in part, to the amount of Si—C bridges in the films. In embodiments, the percentage of carbon atoms bonded to at least two silicon atoms to form Si—C—Si bridge bonds can be 0.03 atomic % or greater, about 0.06 atomic % or greater, about 0.09 atomic % or greater, about 0.12 atomic % or greater, about 0.15 atomic % or greater, about 0.18 atomic % or greater, about 0.21 atomic % or greater, about 0.24 atomic % or greater, or greater. These and other embodiments of the present technology provide a route to forming as-deposited low-κ films from silicon-carbon and oxygen-containing plasma effluents with lower dielectric constants, higher Young's moduli, and higher hardness that can be produced by conventional plasma deposition methods and do not require additional processing operations such as UV curing.

[0049]

[0052] In the foregoing description, for purposes of explanation, numerous details are set forth in order to provide an understanding of various embodiments of the present technology. However, it will be apparent to one skilled in the art that particular embodiments may be practiced without some of these details, or with additional details.

[0050]

[0053] While several embodiments have been disclosed, those skilled in the art will recognize that various modifications, alternative constructions, and equivalents may be used without departing from the spirit of the embodiments. Moreover, in order to avoid unnecessarily obscuring the technology, some well-known processes and elements have not been described. Therefore, the above description should not be construed as limiting the scope of the technology.

[0051]

[0054] Where a range of values is presented, unless the context clearly dictates otherwise, it is understood that each intervening value between the upper and lower limits of that range is also specifically disclosed, to the smallest unit of the unit of the lower limit. Any narrower range between any stated or unstated intervening value in a stated range, and any other stated or intervening value in that stated range, is also encompassed. The upper and lower limits of these smaller ranges may be individually included or excluded in the range, and each range in which either, neither, or both limits are included in the narrower range is also encompassed within the technology, subject to the specifically excluded limit in the stated range. When a stated range includes one or both of the limits, ranges excluding either or both of the included limits are also included.

[0052]

[0055] As used in this specification and the appended claims, the singular forms "a," "an," and "the" include plural referents unless the context clearly dictates otherwise. Thus, for example, reference to a "material" includes a plurality of such materials, reference to a "precursor" includes a reference to one or more precursors and equivalents thereof known to those skilled in the art, and so forth.

[0053]

[0056] Additionally, the terms "comprise(s)", "comprising", "contain(s)", "containing", "include(s)", and "including", when used in this specification and claims, are intended to specify the presence of stated features, integers, components, or steps, but do not exclude the presence or addition of one or more other features, integers, components, steps, operations, or groups.

Claims

1. 1. A semiconductor processing method comprising: flowing a deposition precursor comprising a silicon-containing precursor comprising at least one vinyl group into a substrate processing region of a semiconductor processing chamber; generating a deposition plasma from the deposition precursor in the substrate processing region; depositing a silicon-carbon containing material on a substrate from plasma effluents of the deposition plasma, wherein the as-deposited silicon-carbon containing material is characterized by a dielectric constant of 3.0 or less; and Including, The silicon-carbon containing material is characterized by a methyl group content of greater than 2.5 atomic % and a hardness of 3 GPa or greater. Semiconductor processing methods.

2. The silicon-containing precursor is represented by Formula 1: (In the formula, R １ , R ２ , and R ３ is C １ ~C ６ Alkyl group, or C １ ~C ６ may contain alkoxy groups, and In the formula, R １ , R ２ , and R ３ at least one of which is an alkoxy group 10. The semiconductor processing method of claim 1, characterized by:

3. 10. The semiconductor processing method of claim 1, wherein said silicon-containing precursor comprises vinylmethyldimethoxysilane.

4. The deposition precursor is molecular oxygen (O ２ 10. The semiconductor processing method of claim 1, further comprising:

5. 5. The semiconductor processing method of claim 4, wherein the flow ratio of said molecular oxygen to said silicon-containing precursor is 2:1 or greater.

6. 10. The semiconductor processing method of claim 1, wherein the silicon and carbon containing material is characterized by a Young's modulus of 5 GPa or greater.

7. 1. A semiconductor processing method comprising: flowing a deposition precursor comprising a silicon-carbon-oxygen containing precursor into a substrate processing region of a semiconductor processing chamber; generating a deposition plasma from the deposition precursor in the substrate processing region, the semiconductor processing chamber being characterized by a temperature of 400° C. or greater during generation of the deposition plasma; depositing a silicon-carbon-oxygen containing material on a substrate from plasma effluents of the deposition plasma, wherein the as-deposited silicon-carbon-oxygen containing material is characterized by a dielectric constant of 3.0 or less; Including, the as-deposited silicon-carbon-oxygen containing material is characterized by a hardness of 3 GPa or greater; Semiconductor processing methods.

8. 8. The semiconductor processing method of claim 7, wherein said semiconductor processing chamber is characterized by a temperature of 450° C. or less during generation of said deposition plasma.

9. The deposition precursor is molecular oxygen (O ２ 8. The semiconductor processing method of claim 7, further comprising: a step of: subjecting the molecular oxygen to a gas containing oxygen; and wherein the molecular oxygen has a flow rate into the semiconductor processing chamber of 150 sccm or less.

10. The semiconductor processing method of claim 7, wherein the silicon-carbon-oxygen containing precursor comprises at least one vinyl group.

11. 8. The semiconductor processing method of claim 7, wherein the as-deposited silicon-carbon-oxygen containing material is characterized by a carbon content of 25 atomic % or greater.

12. 8. The semiconductor processing method of claim 7, wherein the as-deposited silicon-carbon-oxygen containing material is characterized by a Young's modulus of 5 GPa or greater.

13. 1. A semiconductor processing method comprising: Silicon-containing precursors and molecular oxygen (O ２ ), wherein the silicon-containing precursor has a flow rate into the semiconductor processing chamber of 2000 mgm or less and the molecular oxygen has a flow rate of 120 sccm or more; generating a deposition plasma from the deposition precursor in the substrate processing region; depositing a silicon-carbon-oxygen containing material on a substrate from plasma effluents of the deposition plasma, wherein the as-deposited silicon-carbon-oxygen containing material is characterized by a dielectric constant of 3.0 or less; Including, the as-deposited silicon-carbon-oxygen containing material is characterized by a hardness of 3 GPa or greater; Semiconductor processing methods.

14. The deposition precursor is helium or nitrogen (N ２ 14. The semiconductor processing method of claim 13, further comprising at least one carrier gas comprising:

15. 14. The semiconductor processing method of claim 13, wherein the flow ratio of said molecular oxygen to said silicon-containing precursor is 2:1 or greater.

16. 14. The semiconductor processing method of claim 13, wherein the silicon-containing precursor comprises at least one vinyl group.

17. 14. The semiconductor processing method of claim 13, wherein the silicon-carbon-oxygen containing material is characterized by a methyl group content greater than 2.5 atomic percent or a carbon content equal to or greater than 25 atomic percent.

18. 14. The semiconductor processing method of claim 13, wherein the as-deposited silicon-carbon-oxygen containing material is characterized by a Young's modulus of 5 GPa or greater.

19. A semiconductor processing method comprising: flowing a deposition precursor comprising a silicon-carbon-oxygen containing precursor into a substrate processing region of a semiconductor processing chamber; generating a deposition plasma from the deposition precursor in the substrate processing region, the semiconductor processing chamber being characterized by a temperature of 425° C. or greater during generation of the deposition plasma; depositing a silicon-carbon-oxygen containing material on a substrate from plasma effluents of the deposition plasma, wherein the as-deposited silicon-carbon-oxygen containing material is characterized by a dielectric constant of 3.0 or less; A semiconductor processing method comprising:

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