Forming halogen doped dielectric films

Abstract

One example provides a method of forming a halogen doped dielectric film. The method includes forming a dielectric film including a plurality of dielectric film layers. The method also includes performing a plasma doping process after forming the dielectric film. The plasma doping treatment comprises introducing a halogen-containing precursor into a plasma; and exposing the dielectric film to a reactive halogen-containing species generated from the halogen-containing precursor in the plasma, thereby forming the halogen-doped dielectric film.

Description

Background Art

[0001] The semiconductor device manufacturing process involves many steps such as material deposition, patterning, and removal to form an integrated circuit on a substrate. Various methods can be used to deposit a material film onto a substrate. As an example, atomic layer deposition (ALD) forms a film layer by layer using multiple deposition cycles (ALD cycles). In an ALD cycle, a film precursor is adsorbed onto the surface of the substrate in a processing chamber. The excess film precursor is removed from the chamber. Then, the adsorbed film precursor is chemically converted into a film on the substrate, for example, by oxidation. Summary of the Invention

[0002] This Summary of the Invention is provided to introduce a selection of concepts in a simplified form that will be further described in the Detailed Description below. This Summary of the Invention is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used to limit the scope of the claimed subject matter. Moreover, the claimed subject matter is not limited to implementations that solve any or all of the disadvantages noted in any part of this disclosure.

[0003] One example provides a method of forming a halogen-doped dielectric film. The method includes forming a dielectric film including a plurality of dielectric film layers. The method further includes performing a plasma doping process after forming the dielectric film. The plasma doping process includes introducing a halogen precursor into a plasma; and exposing the dielectric film to a reactive halogen species generated from the halogen precursor in the plasma, thereby forming the halogen-doped dielectric film.

[0004] In some such examples, the halogen precursor alternatively or additionally includes one or more of fluorine, hydrogen fluoride, nitrogen trifluoride, sulfur tetrafluoride, sulfur hexafluoride, chlorine trifluoride, chlorine pentafluoride, boron trifluoride, phosphorus trifluoride, fluorocarbons, chlorofluorocarbons, chalcogens, hydrofluorocarbons, and interhalogen compounds.

[0005] In some such examples, the halogen precursor alternatively or additionally includes anhydrous HF.

[0006] In some such examples, the halogen precursor alternatively or additionally includes one or more of a chlorine (Cl)-containing substance, a bromine (Br)-containing substance, or an iodine (I)-containing substance.

[0007] In some such examples, the dielectric film alternatively or additionally includes silicon oxide (SiO2).

[0008] In some such examples, the dielectric constant of the halogen-doped dielectric film is alternatively or additionally lower than the dielectric constant of the dielectric film.

[0009] In some such examples, forming the halogen-doped dielectric film alternatively or additionally includes forming a halogen-doped dielectric film, where the halogen extends through the thickness of the halogen-doped dielectric film, the thickness being measured by secondary ion mass spectrometry (SIMS) imaging.

[0010] In some such examples, the method alternatively or additionally further includes heating the substrate to a temperature in the range of 23 °C to 1200 °C when performing the plasma doping process.

[0011] Another example provides a method of forming a halogen-doped dielectric film. The method includes performing a plurality of atomic layer deposition (ALD) cycles. Each ALD cycle includes exposing a substrate in a processing chamber to a dielectric film precursor to adsorb the dielectric film precursor onto the substrate. Each ALD cycle further includes forming a gas mixture in the processing chamber, the gas mixture including a halogen-containing precursor, an oxidant, and an inert gas. Each ALD cycle further includes forming a plasma containing the gas mixture to form a reactive halogen-containing species and a reactive oxidant species; and reacting the dielectric film precursor adsorbed on the substrate with the reactive halogen-containing species and the reactive oxidant species to form the halogen-doped dielectric film.

[0012] In some such examples, the gas mixture alternatively or additionally further includes hydrogen.

[0013] In some such examples, the dielectric film precursor alternatively or additionally includes a silicon-containing precursor.

[0014] In some such examples, the silicon-containing precursor alternatively or additionally includes an aminosilane.

[0015] In some such examples, the halogen-containing precursor alternatively or additionally includes a fluorine-containing precursor.

[0016] In some such examples, the halogen-containing precursor alternatively or additionally includes one or more of fluorine, hydrogen fluoride, nitrogen trifluoride, sulfur tetrafluoride, sulfur hexafluoride, chlorine trifluoride, chlorine pentafluoride, boron trifluoride, phosphorus trifluoride, fluorocarbons, chlorofluorocarbons, chalcogens, hydrofluorocarbons, and interhalogen compounds.

[0017] In some such examples, the halogen-containing precursor alternatively or additionally includes anhydrous HF.

[0018] In some such examples, the halogen-containing precursor alternatively or additionally includes one or more of a chlorine-containing substance, a bromine-containing substance, or an iodine-containing substance.

[0019] Another example provides a processing tool. The processing tool includes a processing chamber, a plasma generator, and one or more gas inlets into the processing chamber. The processing tool also includes flow control hardware fluidly connecting one or more gas sources to the one or more gas inlets. The processing tool also includes a controller. The controller is configured to perform an atomic layer deposition (ALD) process that includes a plurality of ALD cycles to form a dielectric film on a substrate in the processing chamber. The controller is further configured to control the plasma generator to form a plasma after performing the ALD process that includes the plurality of ALD cycles. The controller is further configured to control the flow control hardware to introduce a halogen precursor into the plasma to generate a reactive halogen-containing species, thereby doping the dielectric film with halogen.

[0020] In some such examples, the processing tool alternatively or additionally further includes a substrate heater, wherein the controller is configured to control the substrate heater to heat the substrate to a substrate temperature in the range of 23°C to 1200°C when the dielectric film is exposed to the reactive halogen-containing species.

[0021] In some such examples, the processing tool alternatively or additionally includes a halogen precursor supply source.

[0022] In some such examples, the halogen precursor supply source alternatively or additionally includes one or more of fluorine, hydrogen fluoride, nitrogen trifluoride, sulfur tetrafluoride, sulfur hexafluoride, chlorine trifluoride, chlorine pentafluoride, boron trifluoride, phosphorus trifluoride, fluorocarbons, chlorofluorocarbons, chalcogens, hydrofluorocarbons, and interhalogen compounds. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 A block diagram showing an exemplary processing tool is presented.

[0024] Figure 2 A flowchart showing an exemplary method for forming a halogen-doped dielectric film is presented.

[0025] Figures 3A - 3D Schematically shows in Figure 2 An exemplary substrate structure formed in an exemplary implementation of the process.

[0026] Figure 4 A flowchart showing another exemplary process for forming a halogen-doped dielectric film is presented.

[0027] Figure 5 Schematically shows a reaction zone in a spatial atomic layer deposition (ALD) process.

[0028] Figure 6A top view schematically showing a substrate support that can rotate a substrate through different reaction zones to perform spatial ALD processing.

[0029] Figure 7 A schematic illustration of an exemplary processing chamber configured for spatial ALD.

[0030] Figure 8 A block diagram showing an exemplary computing device. Detailed Description

[0031] The term "aspect ratio" generally refers to the ratio between the depth of a feature of a substrate and the average width of the feature. The term "high aspect ratio (HAR)" generally refers to a feature having a depth:width ratio greater than 1:1.

[0032] The term "atomic layer deposition" (ALD) generally refers to a process in which one or more individual layers of a film are formed on a substrate by sequentially adsorbing precursors onto the substrate and then chemically transforming the adsorbed precursors to form a film layer. Examples of ALD processes include plasma-enhanced ALD (PEALD) and thermal ALD (TALD). PEALD and TALD utilize a plasma of a reactive gas and heat, respectively, to facilitate the chemical transformation of the precursors adsorbed onto the substrate into a film on the substrate. The terms "growth", "deposition", and their variants can also be used to refer to the formation of a film. The term "temporal ALD" generally represents an ALD process in which a film layer is formed by controlling the timing and duration of successive reaction steps while the substrate remains stationary. The term "spatial ALD" generally refers to an ALD process in which a substrate is sequentially moved between different reaction zones, each reaction zone being configured for a specific processing step.

[0033] The terms "atomic layer deposition cycle" and "ALD cycle" generally refer to a single cycle of adsorbing a chemical precursor onto the surface of a substrate and then chemically transforming the adsorbed chemical precursor to form a film layer on the substrate.

[0034] The term "carbon-containing precursor" generally refers to a carbon-containing compound that can be introduced into a processing chamber in the gas phase to form a carbon-containing dielectric film. Exemplary carbon-containing dielectric films include silicon carbide and silicon oxycarbide. Exemplary carbon-containing precursors can include alkanes having the general formula C n H 2n+2 and n is an integer in the range of 1 to 10 (e.g., methane, ethane, etc.), alkenes having the general formula C n H 2n and n is from 2 to 10 (e.g., ethylene, propylene, etc.), and compounds having the general formula C n H 2n-2and n is an alkyne having 2 to 10 carbon atoms (e.g., acetylene, propyne, etc.). Other examples of carbon-containing precursors can include cycloalkanes (including aromatic), nitrogen-containing compounds (including alkylamines), and oxygen-containing compounds (including alcohols, ketones, esters, aldehydes, and ethers) that are in the gas phase under the processing conditions.

[0035] The term "dielectric film" generally refers to a layer of insulating material that can be polarized by an applied electric field. Exemplary dielectric films include silicon oxide (SiO2) films, silicon nitride (Si3N4) films, silicon oxynitride (Si3N 4(1-x) O 6x ) films, silicon carbide (SiC) films, silicon oxycarbide (SiO 2(1-x) C x ) films, aluminum nitride (AlN) films, aluminum oxide (Al2O3) films, tin oxide (e.g., SnO, SnO2) films, gallium nitride (GaN) films, boron nitride (BN), and gallium arsenide (GaAs) films.

[0036] The term "doping" and its variants generally refer to the introduction of impurities into a material to modify one or more physical properties of the material. The term "dopant" generally refers to a chemical substance introduced as an impurity into another material during a doping process.

[0037] The term "flow control hardware" generally refers to components configured to fluidly connect one or more chemical sources to a processing chamber. For example, the flow control hardware can include one or more mass flow controllers and / or valves. Exemplary chemical sources include dielectric film precursor sources, halogen-containing precursor sources, reactive gas sources, and inert gas sources.

[0038] The term "forming a gas mixture" generally refers to mixing a plurality of gases before introducing them into a processing chamber, or either or both of mixing a plurality of gases in the processing chamber.

[0039] The term "halogen doping" and its variants generally refer to a process of doping a dielectric film with a halogen species. Halogens can include fluorine, chlorine, bromine, or iodine. For example, halogen doping can be used to reduce the dielectric constant of a dielectric film such as a silicon oxide film.

[0040] The term "halogen-containing precursor" generally refers to a halogen-containing chemical entity that can be used to dope a dielectric film with a halogen. Examples of fluorine-containing precursors include fluorine (F2), boron trifluoride (BF3), phosphorus trifluoride (PF3), nitrogen trifluoride (NF3), sulfur tetrafluoride (SF4), sulfur hexafluoride (SF6), hydrogen fluoride (HF), chlorine trifluoride (ClF3), chlorine pentafluoride (ClF5), and fluorocarbons, hydrofluorocarbons, chlorofluorocarbons, chalcogens, and interhalogen compounds that are in the gas phase under processing conditions. The term "fluorocarbon" generally refers to a molecule containing one or more carbon atoms and one or more fluorine atoms. The term "hydrofluorocarbon" generally refers to a molecule containing one or more carbon atoms, one or more hydrogen atoms, and one or more fluorine atoms. The term "chlorofluorocarbon" generally refers to a molecule containing one or more carbon atoms, one or more chlorine atoms, and one or more fluorine atoms. The term "interhalogen compound" generally refers to a molecule containing two or more different halogen atoms. The term "chalcogen" generally refers to a molecule containing oxygen, sulfur, selenium, and / or tellurium atoms. Other exemplary halogen-containing precursors include chlorine-containing substances, bromine-containing substances, and iodine-containing substances. Hydrogen chloride (HCl), hydrogen bromide (HBr), and hydrogen iodide (HI) are more specific examples of other halogen-containing precursors.

[0041] The term "inert gas" generally refers to a gaseous material that does not react with other chemical substances in a processing chamber during substrate processing. Exemplary inert gases include helium (He), neon (Ne), argon (Ar), krypton (Kr), and xenon (Xe), and in some processes, nitrogen (N2).

[0042] The term "plasma" generally refers to a gas containing cations and free electrons. The term "in-situ plasma" generally refers to a plasma formed at a processing station in a processing chamber. The term "remote plasma" generally refers to a plasma formed at a location in the processing chamber that is remote from the processing station.

[0043] The term "plasma generator" generally refers to a combination of components that can be used to form a plasma. Exemplary components include a radio frequency power supply, an impedance matching network, and one or more electrodes.

[0044] The term "precursor" generally refers to a chemical substance that adsorbs onto the surface of a substrate during ALD processing. The precursor reacts with a reactant to convert the adsorbed precursor into a film layer.

[0045] The term "processing chamber" generally refers to an enclosure within which chemical and / or physical processing of a substrate is performed. The pressure, substrate temperature, and atmospheric composition within the processing chamber can be controlled to perform chemical and / or physical processing.

[0046] The term "processing tool" generally can denote a machine that includes a processing chamber and other hardware configured to be capable of performing processing in the processing chamber.

[0047] The term "processing station" generally denotes a location in the processing chamber where a substrate is positioned during processing.

[0048] The term "reactant" generally denotes a chemical substance that reacts with a precursor adsorbed to a substrate surface in an ALD process to form a film layer. In various processes, the reaction between the reactant and the precursor can be facilitated by thermal energy and / or plasma.

[0049] The term "silicon-containing precursor" generally denotes a chemical substance that contains one or more silicon atoms and can be adsorbed to a substrate surface in an ALD process to be converted into a silicon-containing dielectric film. Exemplary silicon-containing precursors can include materials having the following general structure: where R1, R2, and R3 can be the same or different substituents and can include silane, siloxanyl, amine, halide, hydrogen, or organic groups such as alkylamine, alkoxy, alkyl, alkenyl, alkynyl, and aryl. More specific exemplary silicon-containing precursors include polysilane (H3Si-(SiH2) n -SiH3), where n≥1, such as silane, disilane, trisilane, tetrasilane, and trisilylamine. In some instances, the silicon-containing precursor is an alkoxysilane. Alkoxysilanes that can be used include the following: H x -Si-(OR) y , where x = 1-3, x + y = 4 and each R is a substituted or unsubstituted alkyl, alkenyl, alkynyl, or aryl group; H x (RO) y -Si-Si-(OR) y H x, is a substituted or unsubstituted alkyl, alkenyl, alkynyl or aromatic group. Other examples of silicon-containing precursors include tetraethyl orthosilicate (TEOS), tetramethoxysilane (TMOS), methylsilane, trimethylsilane (3MS), ethylsilane, butylsilane, pentylsilane, octylsilane, heptylsilane, hexylsilane, cyclobutylsilane, cycloheptylsilane, cyclohexylsilane, cyclooctylsilane, cyclopentylsilane, 1,4-dioxa-2,3,5,6-tetrasilacyclohexane, diethoxymethylsilane (DEMS), diethoxysilane (DES), dimethoxymethylsilane, dimethoxysilane (DMOS), methyldiethoxysilane (MDES), methyldimethoxysilane (MDMS), tert-butoxydisilane, triethoxysilane (TES) and trimethoxysilane (TMS or TriMOS). In some examples, the silicon-containing precursor may include a siloxane. Exemplary siloxanes include octamethylcyclotetrasiloxane (OMCTS), octamethoxydodecasiloxane (OMODDS), tetramethylcyclotetrasiloxane (TMCTS), triethoxysiloxane (TRIES) and tetramethyloxacyclotetrasiloxane (TOMCTS). In addition, in certain examples, the silicon-containing precursor may be an aminosilane, such as bis(diethylamino)silane, diisopropylaminosilane, bis(tert-butylamino)silane (BTBAS), bis(sec-butylamino)silane or tris(dimethylamino)silane (3DMAS). The aminosilane precursor includes the following: H x -Si-(NR) y , where x = 1 - 3, x + y = 4, and R is a substituted or unsubstituted alkyl, alkenyl, alkynyl or aromatic group or a hydride group. In some examples, a halogen-containing silane may be used such that the silane contains at least one hydrogen atom. Such a silane may have the chemical formula SiX a H y , where y ≥ 1. For example, in some examples, dichlorosilane (H2SiCl2) may be used.

[0050] The term "through-substrate via" generally refers to a conductive path that extends through a semiconductor substrate in an integrated circuit.

[0051] As described above, atomic layer deposition (ALD) can be used to deposit a dielectric film. Due to the layer-by-layer nature of ALD film growth, ALD is particularly suitable for forming conformal films in high aspect ratio (HAR) features. As an example of a HAR feature, ALD can be used to line a dielectric layer on a through-substrate via (TSV).

[0052] However, as the feature size of integrated circuits continues to decrease, crosstalk and charge accumulation raise some concerns. Using a dielectric material with a lower dielectric constant helps mitigate the problems of crosstalk and charge accumulation. One way to reduce the dielectric constant of a silicon oxide dielectric film is to dope the silicon oxide dielectric film with fluorine. However, the temperatures used in conventional methods for forming a halogen-doped dielectric film (e.g., a fluorine-doped silicon oxide film) may be too high for some semiconductor manufacturing processes (e.g., damascene processes). In addition, these methods may lack the ability to form a halogen-doped silicon oxide as a conformal film in HAR features.

[0053] A newer method for forming a halogen-doped conformal dielectric film is to use ALD processing, where ALD cycles and halogen doping steps are performed in an alternating manner. First, an ALD cycle is performed to deposit a dielectric film layer. Then, the dielectric film layer is exposed to a halogen precursor in the presence of a plasma to perform a halogen doping step. This processing can be used to form a conformal halogen-doped dielectric film in HAR features at a low temperature suitable for damascene processing. However, compared to forming an undoped dielectric film, performing a plasma doping step after each ALD cycle increases the processing time for forming a halogen-doped dielectric film. Thus, the halogen doping step reduces the throughput compared to the deposition of an undoped dielectric film.

[0054] Accordingly, the present disclosure relates to examples for effectively forming a halogen-doped dielectric film. The disclosed examples can utilize a low temperature suitable for damascene processing. In addition, the disclosed examples can be used to form a conformal halogen-doped dielectric film in HAR features.

[0055] One example disclosed provides a method for forming a halogen-doped dielectric film. The method includes using a plurality of ALD cycles to form a dielectric film containing a plurality of dielectric film layers. The method also includes performing a plasma doping process after forming the dielectric film. The plasma doping process includes introducing a halogen precursor into a plasma. The plasma doping process also includes exposing the dielectric film to a reactive halogen species generated from the halogen precursor in the plasma, thereby forming a halogen-doped dielectric film. In some such examples, the plasma doping process can be performed after the dielectric film is fully formed. Performing the plasma doping process after the dielectric film is fully formed can reduce the processing time and increase the throughput compared to performing a halogen doping step between individual ALD cycles.

[0056] Another example provides a method of forming a halogen-doped dielectric film. The method includes performing a plurality of ALD cycles. Each ALD cycle includes exposing a substrate in a processing chamber to a dielectric film precursor to adsorb the dielectric film precursor to the substrate. Each ALD cycle also includes forming a gas mixture in the processing chamber that includes a halogen-containing precursor, an oxidant, and an inert gas. In some examples, the gas mixture may also include hydrogen. Each ALD cycle also includes forming a plasma that includes the gas mixture to form reactive halogen-containing species and reactive oxidant species, and reacting the dielectric film precursor adsorbed to the substrate with the reactive species to form the halogen-doped dielectric film. In such examples, the halogen doping is performed during the ALD cycles for depositing the respective layers of the dielectric film. This can also reduce the processing time and increase the yield as compared to performing halogen doping between individual ALD cycles.

[0057] Figure 1 FIG. shows a schematic diagram of an exemplary processing tool 100 for performing a deposition process. Processing tool 100 includes an ALD tool. Processing tool 100 can be used to form a halogen-doped conformal dielectric film. Processing tool 100 includes a processing chamber 102. Processing tool 100 also includes a substrate support 104 within processing chamber 102 for supporting a substrate 106. Substrate support 104 can include a pedestal, a chuck, and / or any other suitable structure. Substrate support 104 also includes a substrate heater 108. Processing tool 100 also includes a showerhead 110 located within processing chamber 102. In other examples, nozzles and / or other suitable inlet hardware can be used.

[0058] Processing tool 100 also includes one or more process gas inlets for introducing process gases into processing chamber 102. One exemplary process gas inlet shown is process gas inlet 112. Process gas inlet 112 is configured to allow one or more process gases to flow to showerhead 110 for distribution. Processing tool 100 also includes flow control hardware 114 fluidly connecting a process gas source and processing chamber 102. The process gas source includes a dielectric film precursor source 116, a reactant source A 118, an optional reactant source B 119, a halogen-containing precursor source 120, an inert gas source 122, and an optional hydrogen source 124.

[0059] In some examples, dielectric film precursor source 116 includes a silicon-containing precursor source 126 to form a silicon-based dielectric film having silicon. Exemplary silicon-based dielectric films include silicon oxide, silicon nitride, silicon oxynitride, silicon carbide, and silicon carbonitride. In other examples, dielectric film precursor source 116 may include precursors to form aluminum nitride, aluminum oxide, tin oxide, gallium nitride, boron nitride, or gallium arsenide films.

[0060] The silicon-containing precursor source 126 includes any suitable silicon-containing precursor. Exemplary silicon-containing precursors can include materials having the following general structure: wherein R1, R2, and R3 can be the same or different substituents and can include silanes, silanolates, amines, halides, hydrogen, or organic groups such as alkylamines, alkoxys, alkyls, alkenyls, alkynyls, and aryls. More specific exemplary silicon-containing precursors include polysilanes (H3Si-(SiH2) n -SiH3), where n≥1, such as silane, disilane, trisilane, tetrasilane, and trisilylamine. In some examples, the silicon-containing precursor is an alkoxysilane. Alkoxysilanes available for use include the following: H x -Si-(OR) y , where x = 1-3, x + y = 4 and each R is a substituted or unsubstituted alkyl, alkenyl, alkynyl, or aromatic group; H x (RO) y -Si-Si-(OR) y H x , where x = 1-3, x + y = 4 and each R is a substituted or unsubstituted alkyl, alkenyl, alkynyl, or aromatic group. Further examples of silicon-containing precursors include tetraethyl orthosilicate (TEOS), tetramethoxysilane (TMOS), methylsilane, trimethylsilane (3MS), ethylsilane, butylsilane, pentylsilane, octylsilane, heptylsilane, hexylsilane, cyclobutylsilane, cycloheptylsilane, cyclohexylsilane, cyclooctylsilane, cyclopentylsilane, 1,4-dioxa-2,3,5,6-tetrasilacyclohexane, diethoxymethylsilane (DEMS), diethoxysilane (DES), dimethoxymethylsilane, dimethoxysilane (DMOS), methyldiethoxysilane (MDES), methyldimethoxysilane (MDMS), tert-butoxydisilane, triethoxysilane (TES), and trimethoxysilane (TMS or TriMOS). In some examples, the silicon-containing precursor can include siloxanes. Exemplary siloxanes include octamethylcyclotetrasiloxane (OMCTS), octamethoxydodecasiloxane (OMODDS), tetramethylcyclotetrasiloxane (TMCTS), triethoxysiloxane (TRIES), and tetramethoxycyclotetrasiloxane (TOMCTS). Additionally, in certain examples, the silicon-containing precursor can be an aminosilane, such as bis(diethylamino)silane, diisopropylaminosilane, bis(tert-butylamino)silane (BTBAS), bis(sec-butylamino)silane, or tris(dimethylamino)silane (3DMAS). Aminosilane precursors include the following: H x -Si-(NR) y, where x = 1 - 3, x + y = 4, and R is a substituted or unsubstituted alkyl, alkenyl, alkynyl, or aromatic group or hydride group. In some examples, a halogenated silane can be used such that the silane contains at least one hydrogen atom. Such a silane can have the chemical formula SiX a H y , where y ≥ 1. For example, in some examples, dichlorosilane (H2SiCl2) can be used.

[0061] In some examples, reactant source A 118 includes an oxidant to oxidize the silicon-containing precursor or other dielectric film precursor. Example oxidants include one or more of the following: oxygen (O2), ozone (O3), one or more nitrogen oxides (e.g., N2O), water vapor (H2O), and hydrogen peroxide (H2O2). In some examples, a mixture of two or more different oxidants can be used.

[0062] In other examples, reactant source A 118 can contain nitrogen (N2), ammonia (NH3), or other nitrogen-containing reactants to form a silicon nitride film. In further examples, reactant source A 118 can include reactants that can be used to form silicon carbide from a silicon-containing precursor. Examples thereof include carbon-containing molecules that are gaseous under the processing conditions. More specific examples can include the carbon-containing precursors listed above.

[0063] Optional reactant source B 119 can include reactants for combining with the dielectric precursor and the reactants of reactant source A to form a ternary dielectric film. For example, when the dielectric film is a carbon oxynitride film, reactant source A can include an oxygen-containing reactant, and optional reactant source B can include a carbon-containing reactant. Examples of the oxygen-containing reactant and the carbon-containing reactant include those listed above. Similarly, when the dielectric film is a silicon oxynitride film, reactant source A can include an oxygen-containing reactant, and optional reactant source B can include a nitrogen-containing reactant.

[0064] The halogen-containing precursor source 120 (also referred to herein as the halogen-containing precursor supply source) contains halogen-containing chemicals that can be introduced into the processing chamber 102 in the gas phase. The halogen-containing precursor source 120 can include one or more of a fluorine-containing substance, a chlorine-containing substance, a bromine-containing substance, or an iodine-containing substance. In more specific examples, the halogen-containing precursor source 120 can contain one or more of HF, BF3, PF3, F2, NF3, SF4, SF6, ClF3, ClF5, fluorocarbons, hydrofluorocarbons, or interhalogen compounds that are gaseous under the processing conditions. In further examples, the halogen-containing precursor source 120 can contain hydrogen chloride (HCl), hydrogen bromide (HBr), or hydrogen iodide (HI). The halogen-containing precursor source 120 can include a flow-over-vapor delivery system, where the halogen-containing precursor is HBr or HI.

[0065] The inert gas source 122 can include any suitable gas. Examples thereof include one or more of nitrogen (N2), helium (He), neon (Ne), argon (Ar), krypton (Kr), or xenon (Xe). In some examples, one or more additional inert gas sources can be included, each providing a different inert gas. The inert gas source 122 can be used as a diluent during a deposition process, as a gas for forming a plasma and / or for purging.

[0066] In some examples, hydrogen gas can be used as an additional gas in a dielectric film deposition process and / or a halogen doping process. Accordingly, the flow control hardware 114 can be fluidly connected to an optional hydrogen gas source 124.

[0067] The processing tool 100 further includes an exhaust system 128. The exhaust system 128 is configured to remove gases from the processing chamber 102. The exhaust system 128 can include any suitable hardware. Exemplary hardware includes one or more roughing pumps and / or one or more high vacuum pumps.

[0068] In some examples, the substrate heater 108 is used to provide thermal energy to facilitate a dielectric film deposition process. The substrate heater 108 can further be used to provide thermal energy for a plasma doping process. In these examples, the substrate heater 108 can be used to heat the substrate to a temperature in the range of 23°C to 1200°C.

[0069] In some examples, an in-situ plasma can be used to facilitate a dielectric film deposition process and / or a halogen doping process. The in-situ plasma can be generated using a radio frequency power source A 130 and a matching network A 132. As shown, radio frequency power can be applied to the showerhead 110. Additionally, the substrate support 104 can be connected to electrical ground. In other examples, radio frequency power can be applied to the substrate support 104 and the showerhead 110 can be grounded. The in-situ plasma can be used to provide energy to generate gas-phase chemically active species. In still other examples, radio frequency power of a first frequency and radio frequency power of a second frequency can be applied to the showerhead, where the second frequency is lower than the first frequency.

[0070] In other examples, a remote plasma generator 134 can be used to generate a remote plasma and provide reactive species for a deposition process. The term "remote plasma" generally refers to a plasma to which the substrate is not directly exposed during a deposition process. In contrast, reactive species from the remote plasma diffuse to the substrate 106. In the depicted example, the remote plasma generator 134 is shown to be fluidly coupled to the processing chamber 102 via an inlet 135. In other examples, the remote plasma generator can be adjacent to but remote from the processing chamber. In the case of using the remote plasma generator 134, the processing tool 100 can include a radio frequency power source B 136 that is electrically connected to the remote plasma generator 134. Also, the processing tool 100 can further include a matching network B 138 for impedance matching of the radio frequency power source B 136.

[0071] The radio frequency power source A 130 and the radio frequency power source B 138 can each be configured for any suitable frequency and power. Examples of suitable frequencies include 400 kHz, 13.56 MHz, 27 MHz, 60 MHz, and 90 MHz. Examples of suitable power include power between 50 W (watts) and 50 kW. In some examples, the radio frequency power source A 130 and / or the radio frequency power source B 138 can be configured to operate at multiple different frequencies and / or powers. In some examples, two or more radio frequencies can be used together. Although the processing tool 100 is shown to be configured to generate both a remote plasma and an in-situ plasma, in some examples, the processing tool can be configured to generate either a remote plasma or an in-situ plasma.

[0072] The flow control hardware 114 can be controlled to cause processing chemicals to flow from sources 116, 118, 119, 120, 122, 124, or 126 into the processing chamber 102 via the gas inlet 112. In some examples, the flow control hardware 114 can also be configured to control the flow of one or more chemicals into the remote plasma generator 134. The flow control hardware 114 schematically represents any suitable components associated with causing gases to flow into the processing chamber 102 (and in some examples, the remote plasma generator 134). For example, the flow control hardware 114 can include one or more mass flow controllers and / or valves that can be controlled to fluidly connect the selected chemical sources to the processing chamber 102.

[0073] The controller 140 is operably coupled to the controllable components of the processing tool 100. For example, the controller 140 is operably coupled to the substrate heater 108, the flow control hardware 114, the exhaust system 128, the radio frequency power source A 130, and the radio frequency power source B 136. The controller 140 may also be operably coupled to any other suitable components of the processing tool 100. The controller 140 is configured to control various functions of the processing tool 100 to perform a doped dielectric film deposition process. Exemplary processes are described below.

[0074] Figure 2 Shows a flowchart depicting an exemplary method 200 for forming a halogen-doped dielectric film. The method 200 may be implemented at least in part on a processing tool by computer-readable instructions executed by a controller of the processing tool. The processing tool 100 is an example of a processing tool on which the method 200 may be executed.

[0075] In step 202, the method 200 includes forming a dielectric film containing a plurality of dielectric film layers on a substrate in a processing chamber using ALD. In some examples, the dielectric film may include a silicon oxide film 204. In other examples, the dielectric film may include another dielectric material. Examples thereof include silicon nitride, silicon oxynitride, silicon carbide, silicon oxycarbide, aluminum nitride, aluminum oxide, tin oxide, gallium nitride, boron nitride, and gallium arsenide. The dielectric film includes a plurality of dielectric film layers. Each dielectric film layer is deposited by an ALD cycle. In some examples, the dielectric film may be deposited in HAR features. As an example, the dielectric film may be deposited in a through-substrate via. Each ALD cycle includes exposing the substrate to a dielectric film precursor, purging the deposition chamber, exposing the substrate to a reactant, and purging the deposition chamber again. Plasma may be used to generate reactive species from the reactant. As an example, a silicon oxide film may be formed by exposing the substrate to a silicon-containing precursor and then oxidizing the adsorbed silicon-containing precursor on the substrate to form silicon oxide.

[0076] Figures 3A - 3D Schematically depicts a structure formed in an exemplary implementation of the method 200. First, Figure 3A Schematically depicts a substrate 302 including an etched feature 304. The etched feature 304 may represent a HAR feature formed in a through-substrate via manufacturing process. The dimensions of the substrate 302 and the etched feature 304 are exaggerated and not drawn to scale.

[0077] In a through-substrate via process, the etched feature 304 is ultimately filled with a conductive material to form a conductive path extending through the substrate 302. However, a dielectric film is first deposited in the etched feature 304 to insulate the substrate 302. In Figures 3A - 3DIn [the figure], the sizes of the depicted substrate 302 and the etched feature 304 are enlarged for illustrative purposes. In some examples, the through-substrate via can have an aspect ratio in the range of 1:1 to 300:1. Additionally, in other examples, Figures 3A - 3D can generally represent other HAR features other than the etched features formed during the through-substrate via manufacturing process.

[0078] Figure 3B Depicted is a dielectric film 306 that has been deposited within the etched feature 304 of the substrate 302 using ALD processing. The dielectric film 306 is an example of the dielectric film formed in Figure 2 step 202. The dielectric film 306 is formed by performing a plurality of ALD cycles on the substrate 302 in a processing chamber. As described above, each ALD cycle can include adsorbing a dielectric film precursor onto the surface of the substrate 302. In some examples, the dielectric film precursor can include a silicon-containing precursor. Exemplary silicon-containing precursors include the silicon-containing precursors listed above. After adsorbing the dielectric film precursor onto the surface of the substrate 302, the excess dielectric film precursor in the processing chamber is purged. Then, a plasma is formed. Next, a reactant is introduced into the plasma. The plasma generates reactive species from the reactant. The reactive species converts the dielectric film precursor adsorbed to the substrate into a dielectric film layer. After forming the dielectric film layer, the chamber is purged again to complete the ALD cycle. Multiple ALD cycles can be used to deposit the dielectric film 306 in a layer-by-layer manner. The thickness of the dielectric film 306 can be controlled by controlling the number of ALD cycles used to form the dielectric film 306.

[0079] After forming the dielectric film 306, a plasma doping process is performed. Returning to Figure 2 , method 200 includes introducing a halogen-containing precursor into the plasma at step 206 and exposing the dielectric film to the reactive halogen-containing species generated in the plasma to form a halogen-doped dielectric film. In some examples, the processing chamber is purged before performing the plasma doping process. In other examples, the purge before the halogen doping process can be omitted.

[0080] Figure 3C Schematically depicts an exemplary plasma doping process. As shown, the substrate 302 including the dielectric film 306 is exposed to a plasma 308 including a halogen-containing precursor 310 and an optional inert gas 312. Reactive halogen-containing species are formed in the plasma 308. Then, the reactive halogen-containing species can react with the dielectric film 306 to form a doped dielectric film. Figure 3D Depicts the doped dielectric film 314 formed by plasma doping the Figures 3B - 3C dielectric film 306.

[0081] In some examples, a plasma doping process is performed after deposition of the dielectric film is complete. Performing the plasma doping process after deposition of the dielectric film is complete can reduce the process time as compared to performing a halogen doping process after each ALD cycle. Accordingly, the disclosed examples can help increase substrate throughput. The plasma doping process according to the disclosed examples can introduce halogen throughout the thickness of the film without performing a doping process between each individual ALD cycle. For example, it has been found that by performing a fluorine plasma doping process only after a silicon oxide film is fully formed, fluorine can be introduced into a silicon oxide film having a thickness of 100 nanometers. Additionally, since halogen doping is performed only after the dielectric film is fully formed, compatibility issues between the dielectric film precursor and the halogen-containing precursor can be avoided. In other examples, the plasma doping process can be performed after using multiple ALD cycles to deposit a portion of the dielectric film. This can still help increase substrate throughput as compared to performing a halogen doping process after each ALD cycle. Moreover, the plasma doping process performed after multiple ALD cycles can more effectively utilize the halogen-containing precursor as compared to performing a halogen doping step after each ALD cycle.

[0082] Any suitable halogen-containing chemical that is gaseous under the processing conditions can be used as the halogen-containing precursor. As shown at 208, the halogen-containing precursor can include a fluorine-containing substance, a chlorine-containing substance, a bromine-containing substance, an iodine-containing substance, or a combination of two or more thereof. Exemplary fluorine-containing precursors can include HF, F2, NF3, SF4, SF6, ClF3, ClF5, BF3, PF3, and fluorocarbons, chlorofluorocarbons, chalcogens, hydrofluorocarbons, and interhalogen compounds that are gaseous under the processing conditions, as shown at 210. Examples of such halogen-containing precursors include hydrogen chloride, hydrogen bromide, and hydrogen iodide.

[0083] As a more specific example, anhydrous hydrogen fluoride can be used as the fluorine-containing precursor to dope a silicon oxide film with fluorine. Hydrogen fluoride can etch SiO2 in the presence of water. However, it has been found that anhydrous hydrogen fluoride does not cause etching of the silicon oxide film when used in the disclosed plasma doping process. Additionally, it has been found that anhydrous HF is capable of doping the entire depth of a silicon oxide film up to 100 nanometers thick when applied using the disclosed plasma, as determined by secondary ion mass spectrometry (SIMS).

[0084] In an example where the dielectric film comprises silicon and oxygen (e.g., a SiO2 film) and the halogen dopant comprises fluorine, the halogen dopant reacts with the film to produce Si-F and Si-OF bonds. This reduces the dielectric constant of the fluorine-doped dielectric film as compared to the undoped dielectric film, as Figure 2As shown by 211 in []. For example, compared with an undoped silicon oxide film, the electronegativity of fluorine relative to oxygen reduces the polarizability of a fluorine-doped silicon oxide film. The degree to which halogen doping reduces the dielectric constant depends on the doping degree and the nature of the halogen. For example, at the same dopant concentration, doping with fluorine may result in a lower dielectric constant than doping with chlorine.

[0085] The disclosed halogen doping process can be carried out under any suitable processing conditions. In some examples, the halogen doping process is carried out at a halogen precursor pressure between 0.1 and 760 Torr, as shown by 212. In some examples, this pressure represents the total chamber pressure. In other examples, an inert diluent gas can also be used in addition to the halogen precursor. Increasing the partial pressure of the halogen precursor can increase the absorption rate of the halogen dopant into the dielectric film. This can reduce the time required to perform halogen doping. In addition, in some examples, a flow rate between 50 sccm and 5000 sccm (standard cubic centimeters) can be used to add the halogen precursor to the processing chamber, as shown at 214. A higher halogen dopant ratio can also reduce the time required to perform halogen doping.

[0086] In some examples, as shown at 216, the substrate can be heated to a temperature between 23 degrees Celsius and 1200 degrees Celsius during the plasma doping process. In more specific examples, the substrate can be heated to a temperature between 50 degrees Celsius and 600 degrees Celsius. Such a temperature can be compatible with the damascene process. Increasing the substrate temperature can increase the diffusion rate of the halogen dopant. This can shorten the plasma doping process time and increase the yield. In addition, in some examples, a radio frequency (RF) power in the range of 50 W to 6500 W can be used to form an in-situ plasma during the plasma doping process, as shown by 218. In more specific examples, the RF power can have a power level between 1000 W and 4500 W. In further examples, the RF power plasma can have a power level outside of these ranges. Similarly, the RF power can have any suitable frequency. In some examples, the RF power has a frequency of 13.56 MHz. Other examples of suitable frequencies include 400 kHz, 27 MHz, 60 MHz, and 90 MHz. In some examples, two or more frequencies of RF power can be used to form an in-situ plasma. In some such examples, the RF power of the first frequency can have a power in the range of 50 W to 6500 W, while the RF power of the second frequency can have a power in the range of 100 W to 5000 W, where the second frequency is lower than the first frequency. In other examples, one or more processing conditions outside of these ranges can be used.

[0087] In some examples, in-situ plasma can be used to perform halogen doping processes. As described above, in various examples, the in-situ plasma can be capacitively coupled plasma or inductively coupled plasma. In some examples, an inert gas can also be used in the plasma. Examples of inert gases that can be used include one or more of helium, neon, argon, krypton, or xenon. In other examples, remote plasma can be used to perform halogen doping processes.

[0088] In some examples, deposition and doping can be performed in the same processing tool. Performing dielectric film deposition and plasma doping processes in the same processing tool can reduce the total cycle time and increase the throughput as compared to performing these processes in different processing tools. In other examples, plasma doping processes can be performed in a processing tool different from the processing tool used for depositing the dielectric film.

[0089] In Figure 2 and Figures 3A - 3D examples, halogen doping is performed after multiple ALD cycles are executed to form a dielectric film. Figure 4 A flowchart showing another exemplary method of forming a halogen-doped dielectric film at 400. In method 400, halogen doping is performed during each ALD cycle. This allows avoiding a separate doping process after the dielectric film deposition process. This also avoids a separate doping step between ALD cycles.

[0090] Method 400 includes exposing a substrate in a processing chamber to a dielectric film precursor at step 402, thereby adsorbing the dielectric film precursor to the substrate. In some examples, the dielectric film precursor includes a silicon-containing precursor, as shown in step 404. In some such examples, the silicon-containing precursor can include an aminosilane, as shown in step 406. In other examples, the silicon-containing precursor is in a form other than an aminosilane. Examples of silicon-containing precursors include the silicon-containing precursors listed above. In still other embodiments, dielectric film precursors other than silicon-containing precursors can be used. In some examples, the substrate can be exposed to the dielectric film precursor for a sufficient time to saturate the substrate surface. This helps achieve conformal film growth in HAR features.

[0091] Next, method 400 further includes purging the processing chamber at step 408 after exposing the substrate to the dielectric film precursor. Next, method 400 includes forming a gas mixture at step 410 that includes a halogen-containing precursor, a reactant, and an inert gas. In some examples, the halogen-containing precursor may include one or more of HF, F2, NF3, SF4, SF6, ClF3, ClF5, BF3, PF3, fluorocarbons, chlorofluorocarbons, chalcogens, hydrofluorocarbons, or interhalogen compounds, as shown in step 412. In other examples, the halogen-containing precursor may include one or more of chlorine-containing substances, bromine-containing substances, or iodine-containing substances, as shown in step 414. As an example, the inert gas may include He, Ne, Ar, Kr, Xe, N2, or a combination of two or more thereof. Additionally, as an example, the reactant may comprise O2, O3, H2O2, H2O vapor, N2O, and / or other nitrogen oxides. The term "forming a gas mixture" generally means mixing the gases before introducing the gas mixture into the processing chamber, or mixing one or both of the gases in the processing chamber. In some examples, the halogen-containing precursor is introduced into the processing chamber before the reactant. As a more specific example, after purging the processing chamber, a fluorine-containing precursor may be introduced into the processing chamber first in the absence of the reactant. Next, the fluorine-containing precursor may be introduced together with the reactant and the inert gas for a predetermined period of time while forming a plasma in the processing chamber, as described below. Next, introduction of the fluorine-containing precursor may be stopped while continuing to introduce the reactant and the inert gas into the plasma. Next, the plasma may be extinguished, introduction of the reactant may be stopped, and the chamber may be purged.

[0092] In some examples, the gas mixture may include hydrogen gas, as shown in step 416. In such examples, the hydrogen gas may inhibit etching and thereby facilitate the introduction of fluorine into the dielectric film.

[0093] Next, method 400 further includes forming a plasma containing the gas mixture at step 418. The plasma forms reactive halogen-containing species from the halogen-containing precursor. For example, when the plasma includes a fluorine-containing precursor such as HF, F2, NF3, SF4, SF6, BF3, PF3, or a fluorocarbon, the plasma will convert at least some of the fluorine-containing precursor into excited fluorine species. The excited fluorine species are then incorporated into the growing film in the form of Si-F bonds. The plasma also forms reactive oxidant species from the reactants. In cases where the reactants include oxygen-containing reactants, the plasma can form reactive oxygen-containing species to form an oxide dielectric film. In some examples, the plasma can include an in-situ plasma. In other examples, the plasma can include a remote plasma. As an example, the plasma can include a capacitively coupled radio frequency plasma, an inductively coupled radio frequency plasma, or a microwave plasma. In some examples, the radio frequency power used to form the plasma can have a power level between 50 W and 6500 W. In more specific examples, the radio frequency power can have a power level between 1000 W and 4500 W. In further examples, the radio frequency power plasma can have a power level outside of these ranges. Similarly, the radio frequency power has any suitable frequency. In some examples, the radio frequency power has a frequency of 13.56 MHz. Other examples of suitable frequencies include 400 kHz, 27 MHz, 60 MHz, and 90 MHz. In some examples, radio frequency power at two or more frequencies can be used to form the plasma. In some such examples, the RF power at the first frequency can have a power in the range of 50 W to 6500 W, and the RF power at the second frequency can have a power in the range of 100 W to 5000 W, where the second frequency is lower than the first frequency.

[0094] Method 400 also includes reacting the dielectric film precursor adsorbed to the substrate with the reactive halogen species and the reactive species generated by the reactants. This forms a halogen-doped dielectric film, as shown in step 420. In this way, the dielectric film layer formed via the ALD cycle is halogen-doped. Thus, the doping step between the ALD cycle and the next ALD cycle can be omitted. Similarly, post-deposition doping processes, such as Figure 2 the example shown.

[0095] After forming the halogen-doped dielectric film layer at step 420, the process chamber is purged again at step 422. Then, at step 424, it is determined whether all ALD cycles in the deposition process have been performed. If not, method 400 returns to step 402, where the substrate is again exposed to the dielectric film precursor. On the other hand, if it is determined at step 424 that all ALD cycles have been completed, method 400 ends.

[0096] Thus, the disclosed examples can be used to more effectively form halogen-doped dielectric films, including those in HAR features, than methods that alternately use ALD cycles with halogen doping steps. In some examples, an FSG film having a dielectric constant between 3.6 and 3.7 can be formed. In further examples, an FSG film having a dielectric constant between 3.3 and 3.7 can be formed. Compared to performing a halogen doping process after each ALD cycle, the disclosed examples can increase substrate throughput. Also, the disclosed examples can more effectively utilize halogen-containing precursors than performing a halogen doping step after each ALD cycle.

[0097] The post-ALD halogen exposure treatment can also be used to process seam regions in ALD gap-fill films. A gap is a recessed feature formed in a substrate surface. In integrated circuit manufacturing processes, gaps in the substrate surface are often filled with other materials. As an example, a gap can be filled with a dielectric material such as silicon oxide or a silicon oxide-based material (e.g., silicon oxynitride (SiON)). ALD can be used to fill the gap layer by layer with this material. Each film layer deposited in the gap causes a reduction in the width of the open area of the gap. Eventually, a seam region is formed where the growth fronts of two or more of the films deposited by ALD meet. The seam region may have different properties, such as different densities, compared to the bulk region of the film in the gap. The different properties may cause integrity problems such as structural instability and / or short circuits. The different characteristics may cause integration problems such as structural instability and / or short circuits. Such problems can be alleviated in a variety of ways. As an example, a deposition-etch-deposition (DED) process can be used, where dry etching and / or sputtering steps are used between some or all of the ALD deposition cycles. The dry etching and / or sputtering steps result in V-shaped film growth, where the gap is filled in a bottom-up manner. Another example is to use an inhibitor that inhibits film formation (e.g., by inhibiting precursor adsorption and / or film nucleation). The inhibitor can be deposited on the substrate by adsorbing a first concentration of the inhibitor closer to the opening of the gap in the substrate and a second concentration of the inhibitor closer to the bottom of the gap in the substrate. The second concentration is lower than the first concentration. This allows for bottom-up gap filling.

[0098] However, both the DED and the inhibited ALD methods utilize additional processing steps for the etching / sputtering and inhibitor deposition steps. Compared to processes that omit the etching / sputtering and inhibitor deposition steps, the additional processing steps may increase the processing time and reduce throughput.

[0099] It has been found that exposing a silicon oxide-based gap-fill film to a fluorine-containing plasma can improve the properties of seams in the gap-fill film relative to a gap-fill film not exposed to the fluorine-containing plasma. Unlike the DED and suppressed ALD processes described above, the fluorine-containing plasma treatment can be performed in a post-ALD step. This helps to increase throughput and reduce process complexity compared to the DED and suppressed ALD methods.

[0100] As a more specific example, anhydrous hydrogen fluoride (HF) can be used as a fluorine-containing precursor to improve the seam quality in a silicon oxide gap-fill film. As described above, hydrogen fluoride can etch SiO2 in the presence of water. However, it has been found that plasma treatment using anhydrous hydrogen fluoride improves the seam quality of the silicon oxide gap-fill film. The silicon oxide gap-fill film can contain a relatively higher concentration of terminal -OH groups in the seam region than in other film regions. However, during the post-ALD HF plasma treatment, fluorine species in the plasma can remove the -OH terminal groups from the seam region. Removing the -OH groups can improve Si-O-Si crosslinking. This can improve the seam quality by increasing density and enhancing etch resistance.

[0101] In various examples, the post-ALD HF plasma treatment can be performed after TALD or PEALD. After depositing the silicon oxide gap-fill film, a gas mixture containing anhydrous HF and an inert gas is used to form a plasma. Any suitable inert gas can be used, such as Ar, He, Ne, and N2. In some more specific examples, the gas mixture contains HF, Ar, and N2. In some such examples, the post-ALD HF plasma treatment includes flowing HF at a rate of 50 - 300 sccm, Ar at a rate of 500 to 3000 sccm, and N2 at a rate of 400 to 2400 sccm into the processing chamber. In other examples, flow rates outside of these ranges can be used.

[0102] The post-ALD plasma treatment can be performed under any suitable conditions. Examples of suitable treatment conditions include a pressure of 1 Torr to 20 Torr and a temperature of 250 °C to 750 °C. The post-ALD plasma treatment can be performed for any suitable duration. In some examples, a duration in the range of 1 minute to 10 minutes can be used. In other examples, values outside of these ranges can be used.

[0103] Any suitable plasma conditions can be used for the plasma treatment after ALD. In various examples, by way of example, the plasma can include capacitively coupled radio frequency plasma, inductively coupled radio frequency plasma, or microwave plasma. In some examples, the radio frequency power used to form the plasma can have a power level between 50 W and 6500 W. In more specific examples, the radio frequency power can have a power level between 1000 W and 4500 W. In some examples, a four-station processing tool can use a radio frequency power of about 5000 W to perform the plasma treatment after ALD. In further examples, the radio frequency power plasma can have a power level outside of these ranges. Similarly, the radio frequency power can have any suitable frequency. In some examples, the radio frequency power has a frequency of 13.56 MHz. Other examples of suitable frequencies include 400 kHz, 27 MHz, 60 MHz, and 90 MHz. In some examples, radio frequency power of two or more frequencies can be used to form the plasma, as described above.

[0104] Various experiments have found that the plasma treatment after ALD successfully reduces the wet etch rate (WER) of the film. In one experiment, the WER of the freshly deposited TALD SiO2 film was about After treating the film with anhydrous HF plasma, the WER decreased to about In another experiment, the WER of the freshly deposited TALD SiO2 film was about And after treatment with anhydrous HF plasma, the WER decreased to about

[0105] Before and after the anhydrous HF plasma treatment, Fourier transform infrared spectroscopy (FTIR) was used to analyze various TALD films. The FTIR analysis showed the presence of Si-F bonds in the film after the plasma treatment. In addition, the Si-O band undergoes a blue shift. The FTIR analysis of the TALD film also showed that after the plasma treatment, the -OH band at 3656 cm -1 disappeared.

[0106] In some examples, after performing the HF plasma treatment after ALD, an NH3 plasma treatment can optionally be performed on the ALD gap-fill film. The NH3 plasma treatment can increase the film density and can remove at least some F from the SiO2 gap-fill film.

[0107] In addition, in other examples, an annealing treatment after ALD can be used instead of the plasma treatment. For example, in some experiments, it has been found that an annealing treatment at 950 °C using a co-flow of nitrogen and H2 / O2 can improve the seam quality of certain ALD films.

[0108] The above exemplary ALD method can be implemented on a processing tool configured for temporal ALD (e.g., Figure 1 processing tool 100). Temporal ALD generally refers to using temporal control of gas flow and radio frequency power to achieve successive reaction steps of an ALD process, thereby forming a film layer on a substrate while the substrate is stationary on a pedestal at a processing station. In other examples, spatial ALD can be used to perform the above method. Spatial ALD processing involves moving a substrate between different reaction zones, each configured for a specific processing step. As an example, a processing chamber can be configured to flow multiple different reaction gases through a corresponding plurality of different reaction zones. For example, the reaction zones can be separated by an inert gas flow. Subsequently, a substrate support can rotate the substrate through the different reaction zones.

[0109] Figure 5 Schematically shows reaction zones in an exemplary spatial ALD process 500. The spatial ALD process 500 includes a first reaction zone 502 and a second reaction zone 504. The reaction zones are separated by purge zones 506, 508. The first reaction zone 502 is configured as the dosing step of the ALD process. During the ALD process, the first reaction zone 502 includes a continuous flow of a film precursor 510. Examples of the film precursor 510 include silicon-containing precursors and halogen-containing precursors, such as those listed above.

[0110] In addition, the second reaction zone is configured as the conversion step of the ALD process. During the ALD process, the second reaction zone includes a continuous flow of a reactant compound 512. Examples of the reactant compound 512 include oxidants for oxidizing silicon-containing precursors or other dielectric film precursors. Exemplary oxidants include oxygen, ozone, one or more nitrogen oxides (e.g., nitrous oxide), water vapor, and hydrogen peroxide. In some examples, a mixture of two or more different oxidants can be used. Further examples of the reactant compound 512 include nitrogen (N2), ammonia (NH3), or other nitrogen-containing reactants to form a silicon nitride film. In further examples, the reactant compound 512 can include reactants that can be used to form silicon carbide from a silicon-containing precursor. Examples thereof include carbon-containing molecules that are gaseous under the processing conditions. More specific examples can include the carbon-containing precursors listed above.

[0111] In addition, the purge zones 506, 508 are configured for a continuous flow of an inert gas 514. Examples of the inert gas include He, Ne, Ar, Kr, and N2. The flow 514 of the inert gas helps to remove excess film precursor or reactant compound from the substrate surface.

[0112] During an ALD cycle, the substrate 520 is sequentially moved through the first reaction zone 502, the purge zone 506, the second reaction zone 504, and the purge zone 508 by the substrate support 600. In this way, the substrate is exposed to the film precursor 510 at the first reaction zone 502. Subsequently, the excess film precursor can be removed from the substrate surface at the purge zone 506. Next, the substrate 520 is exposed to the reactant compound 512 at the second reaction zone 504. Subsequently, the excess reactant compound 512 can be removed from the substrate surface at the purge zone 508. Then, the substrate support 600 can move the substrate 520 to the first reaction zone 502 to start another ALD cycle.

[0113] Figure 6 A top view schematically showing an embodiment of the substrate support 600. As Figure 6 shown, the substrate support 600 has a circular shape. The substrate support 600 supports four substrates 520A, 520B, 520C, 520D. During ALD processing, the substrate support 600 is configured to rotate the substrates 520A, 520B, 520C, 520D clockwise through the first reaction zone 502, the purge zone 506, the second reaction zone 504, and the purge zone 508, as indicated by the arrow 602. Although Figure 6 the example depicted shows four substrates being processed, in other examples, any suitable number of substrates can be processed in parallel using spatial ALD processing 500.

[0114] Figure 7 A schematic showing an exemplary processing chamber 700 configured for spatial ALD. The processing chamber 700 includes a substrate support 702 and a top plate 704. The substrate support 702 is configured to support one or more substrates 706. In some examples, the substrate support 702 includes a substrate heater configured to heat the substrate 706. In other examples, the heater can be located at other positions within the processing chamber 700.

[0115] The top plate 704 includes a gas inlet configured to receive gases from one or more gas sources. In the example depicted, the top plate 704 receives gases from a film precursor source 720, a reactant compound source 721, and an inert gas source 722.

[0116] The top plate 704 further includes one or more regions, each region including a corresponding plurality of outlet holes. These outlet holes are disposed on the surface facing the substrate support 702. The top plate 704 is configured to allow a selected process gas to flow through the outlet holes of each region. In this way, the processing chamber 700 can form different reaction zones (e.g., a first reaction zone 502, a second reaction zone 504) corresponding to different regions of the top plate 704 between the substrate support 702 and the top plate 704. Additionally, by flowing an inert gas from the inert gas source 722 through the outlet holes in the selected regions, the processing chamber can form a purge region between the substrate support 702 and the top plate 704.

[0117] The top plate 704 is fixed. The substrate support 702 is configured to rotate relative to the top plate 704. During spatial ALD processing, the substrate 702 rotates, causing the substrate 706 to sequentially move through these reaction zones, as shown above Figure 6 illustrated. The duration of the substrate 706 within each reaction zone can be adjusted by controlling the rotation rate of the substrate support 702. In this way, various aspects of the spatial ALD processing can be controlled by controlling the rotation of the substrate support 702. Further processing conditions for spatial ALD include gas flow rate, pressure, and temperature.

[0118] In some embodiments, the methods and processes described herein may pertain to a computing system of one or more computing devices. In particular, such methods and processes may be implemented as a computer application or service, an application programming interface (API), a library, and / or other computer program products. Figure 8 An example of a computing system 800 that can implement one or more of the above methods and processes is schematically shown. The computing system 800 is shown in simplified form. The computing system 800 may employ one or more personal computers, server computers, tablet computers, network computing devices, and / or other computing devices. Figure 1 The controller 140 is an example of the computing system 800.

[0119] The computing system 800 includes a logic subsystem 802 and a storage subsystem 804. The computing system 800 may optionally include a display subsystem 808, an input subsystem 810, a communication subsystem 812, and / or other components not shown in Figure 8 the figure.

[0120] The logic subsystem 802 includes one or more physical devices configured to execute instructions 806. For example, the logic subsystem may be configured to execute instructions that are part of one or more applications, services, programs, routines, databases, objects, components, data structures, or other logical structures. Such instructions can be implemented to perform tasks, implement data forms, transform the state of one or more components, implement technical effects, or otherwise achieve a desired result. As an example, the logic subsystem may execute instructions for implementing methods 200 and 400 on a processing tool.

[0121] The logic subsystem may include one or more processors configured to execute software instructions. Additionally or alternatively, the logic subsystem may include one or more hardware or firmware logic devices configured to execute hardware or firmware instructions. The processors of the logic subsystem may be single-core or multi-core, and the instructions executed thereon may be configured for sequential, parallel, and / or distributed processing. Individual components of the logic subsystem may be optionally dispersed among two or more separate devices, which may be remotely located and / or configured to coordinate processing. Aspects of the logic subsystem may be virtualized and executed by remotely accessible network computing devices configured in a cloud computing architecture.

[0122] The storage subsystem 804 includes one or more physical devices configured to store instructions 806 executable by the logic subsystem to implement the methods and processes described herein. For example, the storage subsystem 804 may include instructions executable for performing methods 200 and 400. When implementing such methods and processes, the state of the storage subsystem 804 may be transformed—e.g., to store different data.

[0123] The storage subsystem 804 may include removable and / or embedded devices. The storage subsystem 804 may include optical memory (such as CD, DVD, HD-DVD, Blu-ray Disc, etc.), semiconductor memory (such as RAM, EPROM, EEPROM, etc.), and / or magnetic memory (such as hard disk drive, floppy disk drive, tape drive, MRAM, etc.), among others. The storage subsystem 804 may include volatile, non-volatile, dynamic, static, read / write, read-only, random access, sequential access, location-addressable, file-addressable, and / or content-addressable devices.

[0124] It should be understood that the storage subsystem 804 includes one or more physical devices. However, aspects of the instructions described herein may alternatively be propagated via a communication medium (such as electromagnetic signals, optical signals, etc.) that is not stored by a physical device for a limited duration.

[0125] Aspects of the logic subsystem 802 and the storage subsystem 804 may be integrated together into one or more hardware logic components. For example, such hardware logic components may include field programmable gate arrays (FPGAs), application specific and programmable integrated circuits (PASIC / ASICs), application specific and standard products (PSSP / ASSPs), systems on a chip (SOCs), and complex programmable logic devices (CPLDs).

[0126] When included, the display subsystem 808 may be used to present a visual representation of data stored by the storage subsystem 804. The visual representation may take the form of a graphical user interface (GUI). When the methods and processes described herein change the data stored by the storage subsystem and thus the state of the storage subsystem, the state of the display subsystem 808 may also change to visually represent the potential change in the data. The display subsystem 808 may include one or more display devices that virtually utilize any kind of technology. Such display devices may be incorporated with the logic subsystem 802 and / or the storage subsystem 804 in a shared enclosure, or such display devices may be peripheral display devices.

[0127] When included, the input subsystem 810 may include or interface with one or more user input devices (e.g., a keyboard, a mouse, a touch screen). In some implementations, the input subsystem may include or interact with selected natural user input (NUI) components. Such components may be integrated or peripheral, and the translation and / or processing of input actions may be processed on-board or off-board.

[0128] When included, the communication subsystem 812 may be configured to communicatively couple the computing system 800 with one or more other computing devices. The communication subsystem 812 may include wired and / or wireless communication devices that are compatible with one or more different communication protocols. By way of example, the communication subsystem may be configured to communicate using a wireless telephone network, or a wired or wireless local or wide area network. In some embodiments, the communication subsystem may allow the computing system 800 to send messages to and / or receive messages from other devices over a network such as the Internet.

[0129] It should be understood that the configurations and / or methods described herein are exemplary in nature and these specific embodiments or examples are not to be considered limiting as there may be many variations. The specific subroutines or methods described herein may represent one or more of any number of processing strategies. In this regard, the various acts shown and / or described may be performed in the order shown and / or described, in other orders, in parallel, or may be omitted. Similarly, the order of the above-described processes may be changed.

[0130] The subject matter of the present disclosure includes all novel and non-obvious combinations and sub-combinations of various processes, systems, and configurations, as well as other features, functions, acts, and / or properties disclosed herein, and any and all equivalents thereof.

Claims

1. A method of forming a halogen-doped dielectric film, the method comprising: A dielectric film containing a plurality of dielectric film layers is formed on a substrate; And After forming the dielectric film, performing a plasma doping process, the plasma doping process including: Introducing a halogen precursor into the plasma; And Exposing the dielectric film to a reactive halogen-containing species generated from the halogen precursor in the plasma, thereby forming the halogen-doped dielectric film.

2. The method according to claim 1, wherein The halogen precursor includes one or more of fluorine, hydrogen fluoride, nitrogen trifluoride, sulfur tetrafluoride, sulfur hexafluoride, chlorine trifluoride, chlorine pentafluoride, boron trifluoride, phosphorus trifluoride, fluorocarbons, chlorofluorocarbons, chalcogens, hydrofluorocarbons, and interhalogen compounds.

3. The method according to claim 1 or 2, wherein The halogen precursor includes anhydrous hydrogen fluoride.

4. The method according to claim 1, wherein The halogen precursor includes one or more of a chlorine-containing substance, a bromine-containing substance, or an iodine-containing substance.

5. The method according to any one of claims 1 to 4, wherein The dielectric film includes silicon oxide.

6. The method according to any one of claims 1 to 5, wherein, The dielectric constant of the halogen-doped dielectric film is lower than the dielectric constant of the dielectric film.

7. The method according to claim 1, wherein, Forming the halogen-doped dielectric film includes: forming a halogen-doped dielectric film, wherein the halogen extends through the thickness of the halogen-doped dielectric film.

8. The method according to claim 1, further comprising heating the substrate to a temperature in the range of 23°C to 1200°C when performing the plasma doping process.

9. A method of forming a halogen-doped dielectric film, the method comprising: Performing a plurality of atomic layer deposition cycles, each atomic layer deposition cycle including: Exposing a substrate in a processing chamber to a dielectric film precursor to adsorb the dielectric film precursor onto the substrate; Forming a gas mixture in the processing chamber, the gas mixture including a halogen precursor, an oxidant, and an inert gas; Forming a plasma containing the gas mixture to form a reactive halogen-containing species and a reactive oxidant species; And Reacting the dielectric film precursor adsorbed onto the substrate with the reactive halogen-containing species and the reactive oxidant species to form the halogen-doped dielectric film.

10. The method according to claim 9, wherein, The gas mixture further contains hydrogen.

11. The method according to claim 9 or 10, wherein, The dielectric film precursor includes a silicon-containing precursor.

12. The method according to any one of claims 9 to 11, wherein, The silicon-containing precursor contains aminosilane.

13. The method according to any one of claims 9 to 12, wherein, The halogen precursor includes a fluorine-containing precursor.

14. The method according to any one of claims 9 to 13, wherein, The halogen precursor includes one or more of fluorine, hydrogen fluoride, nitrogen trifluoride, sulfur tetrafluoride, sulfur hexafluoride, chlorine trifluoride, chlorine pentafluoride, boron trifluoride, phosphorus trifluoride, fluorocarbons, chlorofluorocarbons, chalcogens, hydrofluorocarbons, and interhalogen compounds.

15. The method according to any one of claims 9 to 14, wherein The halogen precursor includes anhydrous hydrogen fluoride.

16. The method according to any one of claims 9 to 12, wherein, [[ID= ​ ​ ​ ​ ​ ​ ​ After performing the atomic layer deposition process including the plurality of atomic layer deposition cycles, control the plasma generator to form a plasma; and control the flow control hardware to introduce a halogen-containing precursor into the plasma to generate a reactive halogen-containing species, thereby doping the dielectric film with halogen.

18. The processing tool according to claim 17, further comprising a substrate heater, wherein the controller is configured to control the substrate heater to heat the substrate to a substrate temperature in the range of 23°C to 1200°C when exposing the dielectric film to the reactive halogen-containing species.

19. The processing tool according to claim 17 or 18, further comprising a halogen-containing precursor supply source.

20. The processing tool according to any one of claims 17 to 19, wherein The halogen-containing precursor supply source includes one or more of fluorine, hydrogen fluoride, nitrogen trifluoride, sulfur tetrafluoride, sulfur hexafluoride, chlorine trifluoride, chlorine pentafluoride, boron trifluoride, phosphorus trifluoride, fluorocarbons, chlorofluorocarbons, chalcogens, hydrofluorocarbons, and interhalogen compounds.

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