Systems and methods for depositing low-k dielectric films

Abstract

Embodiments of a semiconductor processing method for forming a low dielectric constant film on a semiconductor substrate are described. The processing method may include flowing one or more deposition precursors into a semiconductor processing system, where the one or more deposition precursors include a silicon-containing precursor. The silicon-containing precursor may include a carbon chain. The method may include generating a deposition plasma from the one or more deposition precursors. The method may include depositing a silicon-carbon-containing material on the substrate from plasma effluents of the deposition plasma. The deposited silicon-carbon-containing material may be characterized by a dielectric constant of about 3.0 or less.

Description

[Technical Field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of and priority to U.S. patent application Ser. No. 17 / 896,753, filed Aug. 26, 2022, entitled "SYSTEMS AND METHODS FOR DEPOSITING LOW-K DIELECTRIC FILMS," the entire contents of which are incorporated herein by reference.

[0002]

[0002] The present technology relates to deposition processes and chambers. More particularly, the present technology relates to methods for producing low dielectric constant films that cannot utilize UV ​​processing. [Background technology]

[0003]

[0003] Integrated circuits are made possible by processes that produce 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 the operation of the device and can also affect how films are removed from one another. Plasma-enhanced deposition can produce films with specific properties. Many films that are formed require additional processing to tailor or enhance the material properties of the film to provide the appropriate properties.

[0004]

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

[0005]

[0005] Embodiments of the present technology are described, including a semiconductor processing method for forming a low dielectric constant film on a semiconductor substrate. The processing method can include flowing one or more deposition precursors into a semiconductor processing system, where the one or more deposition precursors include a silicon-containing precursor. The silicon-containing precursor can include a carbon chain. The method can include generating a deposition plasma from the one or more deposition precursors. The method can include depositing a silicon-carbon-containing material on the substrate from plasma effluents of the deposition plasma. The deposited silicon-carbon-containing material can be characterized by a dielectric constant of about 3.0 or less.

[0006] In some embodiments, the silicon-containing precursor has the formula 1: The silicon-carbon-containing material may be characterized by Formula 1, where R is hydrogen, an alkyl group, an alkoxy group, an alkene group, an alkyne group, an acrylate, a halide, NO2, NH2, CN, NCO, NCS, or C=OR, and n is between 1 and 12. The silicon-containing precursor may include a propane chain, a butane chain, a hexane chain, or a heptane chain. The deposition precursor may further include molecular oxygen (O2), diatomic hydrogen (H2), or a combination of both. Generating a deposition plasma from one or more deposition precursors may include forming the deposition plasma in a remote plasma unit. The silicon-carbon-containing material may be characterized by a methyl content of about 2.0 atomic % or greater. The silicon-carbon-containing material may be characterized by a Young's modulus of about 3 GPa or greater. The silicon-carbon-containing material may be characterized by a hardness of about 0.5 GPa or greater.

[0007] Some embodiments of the present technology include a semiconductor processing method. The method can include flowing deposition precursors into a semiconductor processing system. The deposition precursors can include a silicon-containing precursor and a carbon-containing precursor. The carbon-containing precursor can be a chain compound. The method can include generating a deposition plasma from one or more deposition precursors. The method can include depositing a silicon-carbon-containing material on a substrate from plasma effluents of the deposition plasma. The deposited silicon-carbon-containing material can be characterized by a dielectric constant of about 3.0 or less.

[0008] In some embodiments, the temperature can be maintained at about 420°C or less during generation of the deposition plasma. The deposition precursor can further include molecular oxygen (O2). The deposition precursor can further include diatomic hydrogen (H2). Generating the deposition plasma from the one or more deposition precursors can include forming the deposition plasma in a remote plasma unit. The deposited silicon-carbon-containing material can be characterized by a Young's modulus of about 5 GPa or greater.

[0009] Some embodiments of the present technology include a semiconductor processing method. The method can include flowing deposition precursors into a substrate processing region of a semiconductor processing chamber. The deposition precursor can include a silicon-containing precursor. The deposition precursor can include a carbon chain. The method can include generating a deposition plasma from the deposition precursors in the substrate processing region. The method can include depositing a silicon-carbon-containing material on the substrate from plasma effluents of the deposition plasma. The deposited silicon-carbon-containing material can be characterized by a dielectric constant of about 3.0 or less. The deposited silicon-carbon-containing material can be characterized by a Young's modulus of about 4.0 GPa or greater.

[0010] In some embodiments, the silicon-containing precursor may include a carbon chain of the deposition precursor. The deposition precursor may further include at least one carrier gas including helium or nitrogen (N2). Generating the deposition plasma may include applying RF power of about 500 W or less. The flow rate of the deposition precursor may be about 500 mg / min or less. The method may include performing a post-deposition treatment on the silicon-carbon-containing material. The post-deposition treatment may include UV curing or thermal annealing.

[0011]

[0011] Such techniques may offer many advantages over conventional processing methods. For example, utilizing deposition precursors containing carbon chains may increase the presence of closed nanopores within the deposited low-k material. Increasing the amount of closed nanopores in this manner may increase the carbon level in the material without reducing mechanical properties such as Young's modulus and hardness. In addition to forming closed nanopores, the carbon chains may increase the level of carbon within these low-k films, lowering the film's dielectric constant (κ value) to approximately 3.0 or below without simultaneously reducing mechanical stability. Furthermore, increasing the presence of closed nanopores may prevent or reduce the ability of etchants, such as wet etchants, to pass through open pores within the material and damage other layers or regions of the structure. Embodiments of the present technology also include processing methods where deposition of low-k materials may be performed at temperatures above approximately 420°C. Increasing the deposition temperature also increases the amount of Si-C bridges in the low-k material. In further embodiments of the present technology, the deposited low-k material may be characterized by low dielectric constant values ​​and high mechanical stability without undergoing post-deposition UV treatment, which adds additional time and complexity to the processing method. These and other embodiments, along with their many advantages and features, are described in more detail below in the description and accompanying drawings.

[0012] 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 the drawings. [Brief explanation of the drawings]

[0013] [Figure 1] 1 illustrates a top view of an exemplary processing system in accordance with some embodiments of the present technique. [Figure 2]

[0014] 1 shows a schematic cross-sectional view of an exemplary plasma system in accordance with some embodiments of the present technique; [Figure 3]

[0015] 1 illustrates steps of an exemplary method of semiconductor processing in accordance with some embodiments of the present technique. DETAILED DESCRIPTION OF THE INVENTION

[0014]

[0016] Some drawings are included as schematic diagrams. It should be understood that the drawings are for illustrative purposes and should not be considered to be drawn to scale unless specifically stated. Additionally, the figures are provided as schematic diagrams to aid understanding and may not include all aspects or information compared to actual depictions and may include material that is emphasized for illustrative purposes.

[0015]

[0017] In the accompanying drawings, similar components and / or features may have the same reference numerals. Furthermore, various components of the same type may be distinguished according to the reference numerals, with a letter distinguishing between the similar components. When only a first reference numeral is used in this specification, the description may apply to any of the similar components having the same first reference numeral, whatever its letter.

[0016]

[0018] During back-end-of-line (BEOL) semiconductor processing, low-k dielectric films can serve multiple functions in the fabrication of metallization layers within integrated circuits. These functions can include incorporating electrically insulating low-k dielectric films between conductive metal-containing structures such as interconnect lines, contact holes, and vias, among other structures. These functions can also include the partial removal of low-k dielectric films after the formation of metal structures. One common removal process in BEOL is chemical-mechanical polishing (CMP), which uses a combination of chemical etching and physical abrasion to remove low-k dielectric materials from substrate surfaces.

[0017]

[0019] Low-k films used in BEOL processing must have a low dielectric constant (κ) relative to undoped silicon oxide and high mechanical stability to resist damage during the formation of metal-containing structures and their removal by CMP. Unfortunately, these properties are often at odds for low-k films made from silicon- and carbon-containing materials. In many cases, increasing the carbon content in the material reduces the κ value and can also reduce the film's mechanical stability, as characterized by a lower Young's modulus or reduced hardness, among other mechanical properties of the film.

[0018]

[0020] One approach to improving the mechanical stability of low-k films is to treat the deposited film with ultraviolet light (i.e., UV curing / curing steps). Unfortunately, these UV curing steps often involve transferring the substrate from the low-k film deposition chamber to the UV curing chamber, adding time and complexity to the overall low-k film formation process. In most cases, UV light can only penetrate low-k materials to a depth of a few angstroms, so achieving a fully processed low-k film requires shuttle transfer of the substrate between the deposition and curing chambers several times, achieving a low-k film thickness of tens to hundreds of angstroms. Multiple deposition and curing steps can significantly reduce wafer throughput in semiconductor manufacturing processes.

[0019]

[0021] The present technology overcomes these problems by including embodiments of semiconductor processing methods that form low-k films with good mechanical stability. In embodiments, these low-k films may be characterized by a high Young's modulus (e.g., about 5.0 GPa or greater) and high hardness (e.g., about 0.2 GPa or greater). By performing deposition at higher temperatures using specific deposition precursors containing one or more carbon chains, the films may be characterized by an increased level of closed nanopores within the film. This overcomes the natural tendency for the modulus, hardness, and other properties of the film's mechanical stability to decrease as the dielectric constant decreases, and may also reduce the number of steps required during processing. Notably, the present technology may not utilize subsequent post-deposition treatments, including UV exposure, plasma treatment, or other treatment steps, to post-treat the film to improve hardness.

[0020]

[0022] While the remainder of the disclosure will routinely identify specific deposition processes utilizing the disclosed technology, it will be readily understood that these 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 to use with only these specific deposition processes or chambers. This disclosure will discuss one possible system and chamber that may be used to perform a deposition process according to embodiments of the present technology before describing additional details according to embodiments of the present technology.

[0021]

[0023] 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 this illustration, a pair of front-opening unified pods 102 supply substrates of various sizes. These substrates are received by a robotic arm 104 and placed in a low-pressure holding area 106, which is then placed into one of the substrate processing chambers 108a-f located in tandem sections 109a-c. A second robotic arm 110 may 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 steps, including plasma-enhanced chemical vapor deposition, atomic layer deposition, physical vapor deposition, etching, pre-cleaning, pre-cleaning, degassing, orientation, and the formation of semiconductor material stacks as described herein, in addition to other substrate processes including annealing, ashing, and the like.

[0022]

[0024] The substrate processing chambers 108a-f may 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) may be used to deposit a dielectric material on a substrate. A third pair of processing chambers (e.g., 108a-b) may then be used to etch the deposited dielectric. In another configuration, all three pairs of chambers (e.g., 108a-f) may be configured to deposit a stack of alternating dielectric films on a substrate. Any one or more of the processes described may be performed in chambers separate from the fabrication system shown in various embodiments. It will be understood that additional configurations of deposition, etching, annealing, and curing chambers for dielectric films are contemplated by system 100.

[0023]

[0025] 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 illustrate a pair of processing chambers 108 that may be attached to one or more of the tandem sections 109 described above. The pair of processing chambers 108 may include lid stack components in accordance with embodiments of the present technique, which may be described further below. The plasma system 200 may generally include a chamber body 202. The chamber body 202 has 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 include identical components.

[0024]

[0026] 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 to 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.

[0025]

[0027] The body of the pedestal 228 may be coupled to the stem 226 by a flange 233. The stem 226 may electrically couple the pedestal 228 to a power outlet or power box 203. The power box 203 may include a drive system that controls the elevation and movement of the pedestal 228 within the processing region 220B. The stem 226 may also include a power interface for supplying power to the pedestal 228. The power box 203 may also include interfaces for power and temperature indicators, such as a thermocouple interface. The stem 226 may include a base assembly 238 adapted to removably couple with the power box 203. A perimeter ring 235 is shown on the power box 203. In some embodiments, the perimeter ring 235 may be a shoulder adapted as a mechanical stop or land configured to provide a mechanical interface between the base assembly 238 and the upper surface of the power box 203.

[0026]

[0028] A rod 230 is provided through a passage 224 formed in the bottom wall 216 of the processing region 220B and can be utilized to position substrate lift pins 261 disposed through the body of the pedestal 228. The substrate lift pins 261 can selectively space the substrate 229 from the pedestal to facilitate exchange of the substrate 229 by a robot utilized to transfer the substrate 229 into and out of the processing region 220B through the substrate transfer port 260.

[0027]

[0029] 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. The precursor inlet passage 240 may deliver reactants and cleaning precursors into the processing region 220B through 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. The RF source 265 may power 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 faceplate 246 may include one or more openings to allow precursor flow from the precursor distribution system 208 to the processing regions 220A and / or 220B. In some embodiments, the openings may include at least one of linear and conical openings. In some embodiments, an 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 conduction of RF power to the lid 204. A shadow ring 206 may be disposed around the periphery of the pedestal 228, engaging the pedestal 228.

[0028]

[0030] Optional cooling channels 247 may be formed in the annular base plate 248 of the precursor distribution system 208 to cool the annular base plate 248 during operation. A heat transfer fluid, such as water, ethylene glycol, or gas, may be circulated through the cooling channels 247 so that the base plate 248 may be maintained at a predetermined temperature. A liner assembly 227 may be positioned within the processing region 220B proximate the sidewalls 201, 212 of the chamber body 202 to prevent the sidewalls 201, 212 from being exposed to the processing environment within the processing region 220B. The liner assembly 227 may include a peripheral pumping cavity 225. The peripheral pumping cavity 225 may 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 may be formed on the liner assembly 227. The exhaust port 231 can be configured to allow gas flow from the processing region 220B to the peripheral pumping cavity 225 in a manner that facilitates processing within the system 200.

[0029]

[0031] 3 illustrates steps 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 a number of optional steps that may or may not be particularly relevant to some embodiments of the method in accordance with the present technique.

[0030]

[0032] Method 300 may include a plasma enhanced chemical vapor deposition (PECVD) processing step to form a deposited low-k film with high mechanical stability. In contrast to conventional methods, these deposited low-k films do not require post-deposition processing, such as UV curing, to enhance the film's mechanical stability. While post-deposition processing may not be required, it may still be performed in some embodiments to further enhance various film properties. In some embodiments, the method may include optional steps before the start of method 300, or the method may include additional steps after the low-k, mechanically stable material is deposited. In additional embodiments, as shown in FIG. 3 , method 300 may include flowing a deposition precursor into a substrate processing region of a semiconductor processing chamber in step 305. In embodiments, a substrate may be present in the substrate processing region of the semiconductor processing chamber when the deposition precursor flows into the chamber.

[0031]

[0033] The deposition precursor may include a carbon chain. By providing one or more deposition precursors with a carbon chain, closed nanopores may be formed in the film, reducing the dielectric constant and improving the mechanical properties of the film. In embodiments, the deposition precursor may include a silicon-containing precursor. The silicon-containing precursor may include a carbon chain (e.g., CH2-CH2). In additional embodiments, the silicon-containing precursor may be represented by Formula 1: TIFF2025529921000003.tif27170, where each R can be independently selected from an alkyl group (e.g., a C-C alkyl group), an alkoxy group, an alkene group, an alkyne group, an acrylate, a halide, NO, NH, CN, NCO, NCS, or C=OR. In Formula 1, n can be between 1 and 12.

[0032]

[0034] In further embodiments, the silicon-containing precursor includes a precursor having an Si-O bond and / or an Si-C bond, and may include a linear branched silicon-containing precursor, a cyclic silicon-containing precursor, or any number of additional silicon-containing precursors. For example, the silicon-containing precursor may be represented by Formula 2: TIFF2025529921000004.tif26170, wherein each R may be independently selected from an alkyl group (e.g., a C1-C6 alkyl group), an alkoxy group, an alkene group, an alkyne group, an acrylate, a halide, NO2, NH2, CN, NCO, NCS, or C=OR.

[0033]

[0035] In some embodiments, the deposition precursor may further comprise molecular oxygen (O). In embodiments, the flow rate of O relative to the flow rate of the silicon-containing precursor may be maintained at a flow rate ratio that supports the formation of a deposited low-k film having both a low dielectric constant (κ value) and high mechanical stability, particularly as reflected in film properties such as Young's modulus and hardness. Additionally or alternatively, the deposition precursor may also comprise hydrogen, such as diatomic hydrogen (H).

[0034]

[0036] In further embodiments, the deposition precursor may include a carbon-containing precursor. In embodiments, the carbon-containing precursor may include a carbon chain. For example, the carbon-containing precursor may be a hydrocarbon chain or a carbon chain containing other elements such as oxygen. It is contemplated that the carbon-containing precursor may provide a carbon chain, and the silicon-containing precursor may or may not include a carbon chain. Thus, when a carbon-containing precursor having a carbon chain is provided, the silicon-containing precursor may be a conventional silicide for depositing a silicon-containing material. In such embodiments, the carbon-containing precursor may include, for example, an alkyl group, an alkoxy group, an alkene group, an alkyne group, an acrylate, or any other carbon-containing precursor having a carbon chain. For example, the carbon-containing precursor may be a compound represented by Formula 3: TIFF2025529921000005.tif26170, where R can be an alkyl group (e.g., a C-C alkyl group), an alkoxy group, an alkene group, an alkyne group, an acrylate, a halide, NO, NH, CN, NCO, NCS, or C=OR. In Formula 1, n can be between 1 and 12. A and B can be independently selected from C or Si.

[0035]

[0037] In yet another embodiment, the deposition precursors may also include one or more carrier gases, such as helium (He), nitrogen (N), argon (Ar), etc. Although one or more carrier gases may be delivered along with the other deposition precursors, the carrier gases may be considered inert gases and therefore do not react to form part of the deposited low-k material.

[0036]

[0038] In embodiments, the flow rate of the silicon-containing precursor can be about 100 milligrams per minute (mgm) or greater, about 110 mgm or greater, about 120 mgm or greater, about 130 mgm or greater, about 140 mgm or greater, about 150 mgm or greater, about 160 mgm or greater, about 170 mgm or greater, about 180 mgm or greater, about 190 mgm or greater, about 200 mgm or greater, about 210 mgm or greater, about 220 mgm or greater, about 230 mgm or greater, about 240 mgm or greater, about 250 mgm or greater, or greater. The flow rate of the one or more carrier gases can be about 300 sccm or more, about 320 sccm or more, about 340 sccm or more, about 360 sccm or more, about 380 sccm or more, about 400 sccm or more, about 420 sccm or more, about 440 sccm or more, about 460 sccm or more, about 480 sccm or more, about 500 sccm or more, or more.

[0037]

[0039] In some embodiments, it has been observed that an excessive O flow rate relative to a silicon-containing precursor can result in an abnormally large increase in the dielectric constant of the deposited low-k film. It is believed that the excessive O flow rate in such cases increases the number of reactions between oxygen and hydrogen in the film, generating hydroxyl (-OH) groups. In many embodiments, the dielectric constant of a silicon-oxygen-carbon-containing low-k film 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 result in 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 less.

[0038]

[0040] In additional embodiments, deposition precursors flowing into a substrate processing region of a semiconductor processing chamber can change the pressure within the chamber. In embodiments, the semiconductor substrate chamber pressure can be characterized as 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 during formation of a low dielectric constant film. Similarly, the pressure can be characterized as about 10 Torr or less, about 9 Torr or less, about 8 Torr or less, about 7 Torr or less, about 6 Torr or less, about 5 Torr or less, or less.

[0039]

[0041] An embodiment of method 300 may include generating a deposition plasma from a deposition precursor in step 310. In embodiments, the deposition plasma may be generated from the deposition precursor within a substrate processing region of a semiconductor processing chamber, such as by applying RF power to a faceplate to generate a plasma within the processing region. Alternatively, the deposition plasma may be formed remotely from the substrate processing region, such as with a remote plasma system. Forming a remote plasma may maintain a Si-O-Si network within the deposited film. The deposition plasma may be generated at any of the frequencies previously described and may be generated at frequencies less than 15 MHz (e.g., 13.56 MHz). While higher frequencies may be used, in some embodiments, generating a lower frequency plasma may facilitate carbon removal during processing, unlike higher plasma frequency processes. Additionally, the plasma is formed using an RF power of about 1,000 W or less, and may be formed at about 900 W or less, about 800 W or less, about 700 W or less, about 600 W or less, about 500 W or less, about 400 W or less, about 300 W or less, about 250 W or less, about 200 W or less, about 150 W or less, about 100 W or less, or less.

[0040]

[0042] Embodiments of method 300 may include depositing a low-k film on a substrate in step 315. In embodiments, the substrate resides in a substrate processing region of a semiconductor processing chamber, and the low-k film is formed from deposition plasma effluents generated by a deposition plasma also present in the processing region. In some embodiments, the substrate may be characterized by a temperature of about 420°C or less, about 410°C or less, about 410°C or less, about °C or less (less than or about 410°C, less than or about 410°C, less than or about °C), about 380°C or less, about 370°C or less, about 360°C or less, about 350°C or less, about 340°C or less, about 330°C or less, about 320°C or less, about 310°C or less, about 300°C or less, about 290°C or less, about 280°C or less, about 270°C or less, or less. In embodiments, the temperature of the substrate may be set to increase the amount of Si-C crosslinking in the deposited low-k film. Increasing Si-C crosslinking can enhance the mechanical stability of low-k films. In embodiments, the deposited low-k films may be characterized by an increased Young's modulus and increased hardness at higher temperatures. However, excessively high temperatures can volatilize carbon and outgas the film during deposition of the low-k film. Excessively high temperatures can also remove significant amounts of carbon from the low-k film as carbon oxides (e.g., CO, CO) and volatile organic compounds (e.g., -CH, CH), reducing the carbon level in the film. As the carbon level decreases, the film's dielectric constant (κ value) can increase 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 may be characterized by a temperature of about 450°C or less during deposition of the low-k film.

[0041]

[0043] In some embodiments, the deposition rate of low-k films can be greater than 10 Å / min, about 15 Å / min or greater, about 20 Å / min or greater, about 50 Å / min or greater, about 100 Å / min or greater, about 150 Å / min or greater, about 200 Å / min or greater, about 250 Å / min or greater, about 300 Å / min or greater, about 400 Å / min or greater, about 500 Å / min or greater, or even greater. After deposition to a sufficient thickness (e.g., about 1000 Å or less), many conventional processes may then transfer the substrate to a second chamber to perform treatments such as UV treatments or post-deposition treatments. This can reduce throughput and increase manufacturing costs by requiring additional chambers or tools to perform the treatments. However, the present technology can produce materials including silicon-carbon-containing materials (e.g., carbon-doped silicon oxide), which can be characterized by sufficient material properties in the as-deposited state without additional treatments such as UV treatments. Although embodiments of the present technology may include additional post-deposition processing, the as-deposited properties of the film may include various improvements over prior art.

[0042]

[0044] As described above, the processing methods of the present technology may include embodiments utilizing deposition precursors and processing conditions that form low-k films with low dielectric constants and high mechanical stability. In embodiments of processing method 300, the deposited low-k films may be formed as silicon-carbon-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, about 2.5 or less, about 2.4 or less, about 2.3 or less, about 2.2 or less, about 2.1 or less, about 2.0 or less, or even lower. The low dielectric constant of the films may be due, at least in part, to the porosity of the films. In embodiments, precursors containing carbon chains can be used to form closed nanopores within the films. The formation of closed nanopores reduces the dielectric constant of the films while maintaining mechanical stability. With conventional film formation, the aforementioned dielectric constants are only possible with highly porous atomic-scale networks, typically requiring porogens and / or spin-on application methods.

[0043]

[0045] In some embodiments, the decrease in the dielectric constant (κ value) and increased mechanical stability of low-k films may be correlated with an increased level of methyl groups as a fraction of the total carbon in the film. Retention of methyl groups in low-k films may maintain a higher atomic percentage of carbon in the material, resulting in a lower dielectric constant. However, methyl groups are believed to have less of a destabilizing effect on the mechanical properties of low-k films compared to other hydrocarbon groups. In embodiments, the increased level of methyl groups may be partially attributable to deposition precursors containing at least one carbon chain. To form methyl groups, carbon chains can be readily hydrogenated at deposition temperatures. The deposited low-k films may be characterized by the atomic (i.e., molecular) percentage of methyl groups (—CH3) relative to silicon oxide (SiO) groups in the low-k 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 greater than 2.5 atomic %, greater than 2.75 atomic %, greater than or equal to about 3 atomic %, greater than 3.25 atomic %, greater than 3.5 atomic %, greater than 3.75 atomic %, greater than 4 atomic %, or more. Similarly, the atomic percentage of methyl groups can be less than or equal to about 10.0 atomic %, less than or equal to about 9.5 atomic %, less than or equal to about 9.0 atomic %, less than or equal to about 8.5 atomic %, less than or equal to about 8.0 atomic %, less than or equal to about 7.5 atomic %, less than or equal to about 7.0 atomic %, or less.

[0044]

[0046] The processing methods of the present technology include embodiments that produce deposited low-k films characterized by high mechanical stability. In embodiments, the deposited low-k films are characterized by a Young's modulus of about 3.0 GPa or greater, and may be characterized by a Young's modulus of about 3.5 GPa or greater, about 4.0 GPa or greater, about 4.5 GPa or greater, about 5.0 GPa or greater, about 5.5 GPa or greater, about 6.0 GPa or greater, about 6.5 GPa or greater, about 7.0 GPa or greater, about 7.5 GPa or greater, about 8.0 GPa or greater, about 8.5 GPa or greater, or even greater. In further embodiments, the deposited low-k films are characterized by a hardness of about 0.2 GPa or greater, and may be characterized by a hardness of about 0.3 GPa or greater, about 0.4 GPa or greater, about 0.5 GPa or greater, about 0.6 GPa or greater, about 0.7 GPa or greater, or even greater. These and other embodiments of the present technology provide a path to forming low dielectric constant films deposited from silicon-containing plasma effluents that have lower dielectric constants, higher Young's moduli, and higher hardness, which can be fabricated using conventional plasma deposition methods and without the need for additional processing steps such as UV curing.

[0045]

[0047] In the preceding description, for purposes of explanation, numerous details have been 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.

[0046]

[0048] Although several embodiments have been disclosed, those skilled in the art will recognize that various modifications, alternative structures, and equivalents can be used without departing from the spirit of the embodiments. Additionally, some well-known processes and elements have not been described to avoid unnecessarily obscuring the technology. Therefore, the above description should not be construed as limiting the scope of the technology.

[0047]

[0049] Where a range of values ​​is given, unless the context clearly indicates otherwise, it is understood that each intervening value between the upper and lower limit of that range is specifically disclosed, to the smallest fraction 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 such narrower ranges may individually be included or excluded within that range. Each range where either, neither, or both limits are included within this narrower range is also encompassed within the technology, even though there may be specifically excluded limits within the stated range. When a stated range includes one or both of the limits, ranges excluding either or both of those included limits are also included.

[0048]

[0050] As used in this specification and the appended claims, the singular forms "a," "an," and "the" include plural references unless the context clearly dictates otherwise. Thus, for example, a reference to "a material" includes a plurality of such materials, and a reference to "the precursor" includes a reference to one or more precursors and equivalents thereof known to those skilled in the art.

[0049]

[0051] 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 one or more deposition precursors into a semiconductor processing system, the one or more deposition precursors comprising a silicon-containing precursor, the silicon-containing precursor comprising a carbon chain; generating a deposition plasma from the one or more deposition precursors; depositing a silicon-carbon containing material onto a substrate from plasma effluents of the deposition plasma, the deposited silicon-carbon containing material being characterized by a dielectric constant of about 3.0 or less; A method comprising:

2. The silicon-containing precursor has the formula 1: wherein R is hydrogen, alkyl, alkoxy, alkene, alkyne, acrylate, halide, NO ２ , N.H. ２ , CN, NCO, NCS, or C=OR, and n is between 1 and 12.

3. 10. The semiconductor processing method of claim 1, wherein the silicon-containing precursor comprises a propane chain, a butane chain, a hexane chain, or a heptane chain.

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

5. 5. The semiconductor processing method of claim 4, wherein generating the deposition plasma from the one or more deposition precursors comprises forming the deposition plasma in a remote plasma unit.

6. 10. The semiconductor processing method of claim 1, wherein said silicon-carbon containing material has a methyl content of about 2.0 atomic percent or greater.

7. 2. The semiconductor processing method of claim 1, wherein the silicon-carbon containing material has a Young's modulus of about 3 GPa or greater.

8. 2. The semiconductor processing method of claim 1, wherein the silicon-carbon containing material has a hardness of about 0.5 GPa or greater.

9. 1. A semiconductor processing method comprising: flowing deposition precursors into a semiconductor processing system, the deposition precursors comprising a silicon-containing precursor and a carbon-containing precursor, the carbon-containing precursor being a chain compound; generating a deposition plasma from one or more of said deposition precursors; depositing a silicon-carbon containing material onto a substrate from plasma effluents of the deposition plasma, the deposited silicon-carbon containing material being characterized by a dielectric constant of about 3.0 or less; A method comprising:

10. 10. The semiconductor processing method of claim 9, wherein a temperature is maintained at or below about 420°C during generation of the deposition plasma.

11. The deposition precursor is molecular oxygen (O ２ 10. The semiconductor processing method of claim 9, further comprising:

12. The deposition precursor is diatomic hydrogen (H ２ 10. The semiconductor processing method of claim 9, further comprising:

13. 10. The semiconductor processing method of claim 9, wherein generating the deposition plasma from one or more of the deposition precursors comprises forming the deposition plasma in a remote plasma unit.

14. 10. The semiconductor processing method of claim 9, wherein the deposited silicon-carbon containing material has a Young's modulus of about 5 GPa or greater.

15. 1. A semiconductor processing method comprising: flowing a deposition precursor into a substrate processing region of a semiconductor processing chamber, the deposition precursor comprising a silicon-containing precursor, the deposition precursor comprising a carbon chain; generating a deposition plasma from the deposition precursor in the substrate processing region; depositing a silicon-carbon containing material onto a substrate from plasma effluents of the deposition plasma, the deposited silicon-carbon containing material being characterized by a dielectric constant of about 3.0 or less, and the deposited silicon-carbon containing material being characterized by a Young's modulus of about 4.0 GPa or more; A method comprising:

16. 16. The semiconductor processing method of claim 15, wherein the silicon-containing precursor comprises the carbon chain of the deposition precursor.

17. The deposition precursors are helium or nitrogen (N ２ 16. The semiconductor processing method of claim 15, further comprising at least one carrier gas comprising:

18. 16. The semiconductor processing method of claim 15, wherein generating the deposition plasma comprises applying an RF power of about 500 W or less.

19. 16. The semiconductor processing method of claim 15, wherein the deposition precursor flow rate is less than or equal to about 500 mg / min.

20. 16. The semiconductor processing method of claim 15, further comprising performing a post-deposition treatment on the silicon-carbon containing material, wherein the post-deposition treatment comprises a UV cure or a thermal anneal.

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