Composition for films containing silicon and boron and method using the same

Abstract

The present invention provides a composition for films containing silicon and boron, and a method for using the same. [Solution] The present invention relates to a composition and a method for using the composition for forming a film containing silicon and boron, in particular, having a low dielectric constant (less than 6.0) and high oxygen ashing resistance, in the manufacture of electronic devices. The film contains silicon and boron, and is not limited to silicon borocarboxylate, silicon borocarbonitride, silicon boroxide, or silicon borocarboxynitride.

Description

Technical Field

[0001] This specification describes compositions and methods for the manufacture of electronic devices. More specifically, this specification describes, but is not limited to, compounds for forming low dielectric constant (less than 6.0) and high oxygen ashing resistant films containing silicon and boron, such as silicon borocarboxide, silicon borocarbonitride, silicon boroxide, and silicon borocarboxynitride, via atomic layer deposition, as well as compositions and methods containing the same.

Background Art

[0002] In the relevant art, there is a need to provide compositions and methods of using the same for forming films containing silicon and boron having a high boron content (e.g., a boron content of about 10 atomic % or more measured by X-ray photoelectron spectroscopy (XPS)) for specific applications within the electronics industry.

[0003] US6093840 discloses silylalkylboranes having the general formula I, R 1 R 2 R 3 SiC(R 4 )C(R 5 R 6 H)BR 7 R 8 (wherein, R 1~3 = C1-6 alkyl, vinyl, Ph, H, or halogen; R 4~6 = C1-6 alkyl, vinyl, Ph, and / or H; R 7 , R 8 = chloride and / or bromide), and each Si atom and each B atom are coordinated at 3 and 2 R sites, respectively, and Si and B are bonded via a C(CR 5 R 6 H)(R 4 ) bridge. Silicon borocarbonitride ceramics are produced by pyrolyzing oligomers and polyborocarbosilazanes with ≧1 in NH3 or an inert gas at -200 °C or higher and 2000 °C or lower, and firing at 800 °C or higher and 2000 °C or lower.

[0004] US6815350 and US6962876 disclose a method for forming a low dielectric layer for semiconductor devices using an ALD process that includes: (a) forming a predetermined interconnection pattern on a semiconductor substrate; (b) supplying a first reactive substance and a second reactive substance to a chamber having the substrate in it, thereby adsorbing the first reactive substance and the second reactive substance onto the surface of the substrate; (c) supplying a first gas to the chamber to purge any unreacted first and second reactive substances; (d) supplying a third reactive substance to the chamber to induce a reaction between the first and second reactive substances and the third reactive substance to form a monolayer; (e) supplying a second gas into the chamber to purge any unreacted third reactive substance and by-products remaining in the chamber; and (f) repeating steps (b) through (e) a predetermined number of times to form a SiBN ternary layer having a predetermined thickness on the substrate.

[0005] US9293557B and US9590054B disclose semiconductor structures including boron nitride (BN) spacers on gate stacks, such as gate stacks for planar FETs or FinFETs, and methods for manufacturing the same. Boron nitride spacers are manufactured using atomic layer deposition (ALD) and / or plasma-assisted atomic layer deposition (PEALD) techniques to produce boron nitride spacers at relatively low temperatures suitable for devices made from materials such as silicon (Si), silicon germanium (SiGe), germanium (Ge), and / or III-V compounds. Furthermore, boron nitride spacers can be manufactured to have a variety of desirable properties, including hexagonal texture structures.

[0006] US9520282 discloses a method for manufacturing a semiconductor device, comprising: treating the surface of an insulating film formed on a substrate by supplying a first precursor containing a predetermined element and a halogen group to the substrate; and forming a thin film containing the predetermined element on the treated surface of the insulating film by performing a predetermined number of cycles, wherein each cycle includes supplying a second precursor containing the predetermined element and a halogen group to the substrate; and supplying a third precursor to the substrate.

[0007] US20140170858A discloses a method for forming a film on a substrate by performing a predetermined number of cycles, the cycles comprising supplying a raw material gas to the substrate, wherein the raw material gas contains the predetermined element, chlorine, and oxygen, and the predetermined element and oxygen are chemically bonded; and supplying a reactive gas to the substrate, wherein the reactive gas contains at least one element selected from the group consisting of nitrogen, carbon, and boron.

[0008] US2013052836A discloses a method for manufacturing a semiconductor device, comprising the steps of: supplying one of a chlorosilane-based raw material and an aminosilane-based raw material to a substrate in a processing chamber, and then supplying the other raw material to form a first layer on the substrate containing silicon, nitrogen, and carbon; and supplying a reactive gas different from each raw material to the substrate in the processing chamber to modify the first layer and form a second layer; and performing these steps alternately a predetermined number of times to form an insulating film having a predetermined composition and predetermined film thickness on the substrate.

[0009] US20140273507A discloses a method for manufacturing semiconductor devices. The method includes forming a thin film having a borazine ring skeleton and containing a predetermined element, boron, carbon, and nitrogen, on a substrate by performing a predetermined number of cycles. The cycles include supplying a precursor gas containing the predetermined element and a halogen element to the substrate, supplying a reactive gas containing an organoborazine compound to the substrate, and supplying a carbon-containing gas to the substrate. The cycles were performed under conditions in which the borazine ring skeleton in the organoborazine compound was maintained.

[0010] R. Southwick et al. (2015), A Novel ALD SiBCN Low-k Spacer for Parasitic Capacitance Reduction in FinFETs, 2015, Symposium on VLSI Technology, Kyoto, Japan, discloses the identification of a novel low-temperature ALD-based SiBCN material, along with an optimized spacer RIE process developed to maintain low-k values ​​and provide compatibility with downstream processes. The material was integrated into a manufacturable 14nm replacement metal-gate (RMG) FinFET baseline and demonstrated an approximately 8% improvement in RO delay with reliability meeting technical requirements. The report also provides guidance for spacer design considerations beyond the 10nm node, based on comprehensive material properties and reliability evaluations.

[0011] US9472391B discloses a method for manufacturing a semiconductor device, comprising forming a thin film containing silicon, oxygen, carbon, and a specific group III or group V element on a substrate by performing a predetermined number of cycles. The cycles include supplying a precursor gas containing silicon, carbon, and halogen elements and having Si-C bonds, and a first catalyst gas to the substrate; supplying an oxidizing gas and a second catalyst gas to the substrate; and supplying a reforming gas containing a specific group III or group V element to the substrate.

[0012] According to Yang, SR et al. (2006) Low k SiBN (Silicon Boron Nitride) Film Synthesized by a Plasma-Assisted Atomic Layer Deposition. ECS Transactions, 1, 79, SiBN films were fabricated by plasma-assisted atomic layer deposition (PAALD) using dichlorosilane, boron trichloride, and ammonia as source gases. In this material system, nitrogen reacts more readily with boron than with silicon, making reaction control of boron, silicon, and nitrogen a crucial issue. On the other hand, ammonia radicals generated by remote plasma in PAALD promote the reaction between silicon and nitrogen. Therefore, PAALD can enhance the controllability of silicon and boron content. When a SiBN film with a dielectric constant of 4.45 to 5.47 was applied as a buried contact (BC) spacer in place of a SiN film in a 70nm DRAM device, the bit line load capacitance (CBL) decreased by 12% to 24%. Low-k SiBN films deposited using PAALD are promising as insulating interlayer materials, such as Si3N4 spacers, for future sub-70nm DRAM devices.

[0013] Previously identified patents, patent applications, and publications are incorporated herein by reference. [Overview of the Initiative]

[0014] The compositions and methods described herein have the following characteristics: i) the etching rate measured in dilute hydrofluoric acid is 0.5 times or less the etching rate of thermal silicon oxide (e.g., 0.45 Å / s in 1:99 dilute hydrofluoric acid), and the boron content measured by X-ray optical spectroscopy (XPS) is between approximately 5 atomic weight percent and approximately 45 atomic weight percent (at%); ii) the dielectric constant is 6 or less, and the wet etching rate in dilute HF (dHF) is not sensitive to damage during the oxygen ashing process or exposure to oxygen plasma. The problems of the prior art are overcome by providing a composition or formulation for forming a conformal film containing silicon and boron having one or more of the following: iii) the film's dielectric constant after O2 ashing is less than 50 Å as measured by dHF dip, and is less than 4.0; iii) the dielectric constant is less than 6.0, preferably less than 5, most preferably less than 4; and iv) the chlorine impurities in the resulting film are less than 2.0 at%, preferably less than 1.0 at%, most preferably less than 0.5 at%. Desired properties that can be achieved by the present invention are illustrated in more detail in the following examples.

[0015] In a particular embodiment, the compositions described herein can be used in a method for depositing silicon and boron-containing films using atomic layer deposition (ALD) employing a precursor having one Si-CB bond as shown in Table 1.

[0016] Table 1. Precursors having one Si-CB bond. [ka] In one aspect, a composition for forming a film containing silicon and boron comprises: (a) at least one precursor compound described in Table 1 and having at least one Si-C-B bond in at least one embodiment of the present invention; and (b) at least one solvent. In certain embodiments of the compositions described herein, exemplary solvents can include, but are not limited to, ethers, tertiary amines, alkyl hydrocarbons, aromatic hydrocarbons, siloxanes, tertiary aminoethers, and combinations thereof. In certain embodiments, the difference between the boiling point of the silicon compound and the boiling point of the solvent is 40 °C or less, less than about 30 °C, in some cases less than about 20 °C, and preferably less than 10 °C.

[0017] In another aspect, a method for forming a film containing silicon and boron on at least the surface of a substrate is provided, the method comprising: placing the substrate in an ALD reactor; heating the reactor to one or more temperatures in the range of about 25 °C or more and about 700 °C or less; introducing into the reactor a precursor comprising at least one compound selected from the compositions containing the precursors shown in Table 1 and combinations thereof; introducing a nitrogen source or an oxygen source into the reactor to react with at least a portion of the precursor to form a film containing silicon and boron; optionally, treating the resulting film containing silicon and boron with an oxygen source at one or more temperatures in the range of about 25 °C or more and about 1000 °C or less, or about 100 °C or more and about 400 °C or less, under conditions sufficient to convert the film into a silicon boron carbonitride film or a silicon boron carboxynitride film; and comprising.

[0018] In certain embodiments, the silicon and boron-containing film has a boron content of about 10 atomic weight percent (at%) or more as measured by XPS, a carbon content of about 5 atomic weight percent (at%) or more as measured by XPS, and an etching rate of at least 0.5 times that of thermal silicon oxide as measured in dilute hydrofluoric acid. In some embodiments, the silicon and boron-containing film is a silicon carbonitride. In other embodiments, the silicon and boron-containing film is a silicon borocarbonitride or a silicon borocarboxynitride.

[0019] If necessary, the present invention further includes treating a film containing silicon and boron with a hydrogen plasma or hydrogen / inert plasma at a temperature of 25°C to 700°C to densify the resulting film and reduce its dielectric constant.

[0020] Another aspect of the present invention is, (a) Having one Si-CB bond, and comprising at least one precursor compound selected from the group consisting of (trichlorosilyl)(dichloroboryl)methane, 1-(trichlorosilyl)-1-(dichloroboryl)ethane, 2-(trichlorosilyl)-2-(dichloroboryl)propane, and (dichloromethylsilyl)(dichloroboryl)methane, (b) at least one solvent, This relates to compositions containing the following:

[0021] Further aspects of the present invention relate to a film comprising silicon and boron with k of about 6 or less, preferably about 5 or less, most preferably about 4 or less, having a boron content of at least about 10 at%. Further aspects of the present invention relate to a film. Further aspects of the present invention relate to a film comprising silicon and boron, with k of about 6 or less, preferably about 5 or less, most preferably about 4 or less, and having a boron content of at least about 10 at%, preferably at least about 15 at%, most preferably at least about 20 at% based on XPS measurement. In another aspect, the film of the present invention can be formed according to any of the methods of the present invention. Since carbon content is an important factor for reducing the wet etching rate and improving ashing resistance, the carbon content according to the present invention is in the range of 5 at% to 30 at%, preferably 10 at% to 30 at%, most preferably 20 at% to 30 at% as measured by XPS.

[0022] Another aspect of the present invention relates to a stainless steel container for housing the composition of the present invention.

[0023] The embodiments of the present invention can be used individually or in various combinations with each other. [Modes for carrying out the invention]

[0024] This specification describes, but is not limited to, precursor compounds, compositions, and methods for depositing silicon and boron-containing carbon-doped films (e.g., having a boron content of about 10 at% or more as measured by XPS) via deposition processes such as thermal atomic layer deposition. Films deposited using the compositions and methods described herein exhibit extremely low etching rates (e.g., about 0.20 Å / sec or less or about 0.15 Å / sec or less in dilute HF (0.5 wt%)), such as 0.5 times or less the etching rate of thermal silicon oxide measured in dilute hydrofluoric acid, or 0.1 times or less the etching rate of thermal silicon oxide, or 0.05 times or less the etching rate of thermal silicon oxide, or 0.01 times or less the etching rate of thermal silicon oxide, while exhibiting, but is not limited to, variability in other tunable properties such as density, dielectric constant, refractive index, and elemental composition.

[0025] In certain embodiments, the precursors and methods using them described herein impart one or more of the following characteristics in the following ways: First, a Si-CB bond-containing precursor and a nitrogen source are used to form an as-deposited reactive carbon-doped silicon nitride film. While we do not wish to be bound by any theory or explanation, it is believed that the Si-CB bond from the precursor remains in the resulting as-deposited film and provides a high boron content of at least 10 at% (e.g., about 20 at% to about 45 at%, about 20 at% to about 40 at%, and possibly about 15 at% to about 40 at%) as measured by XPS. Second, when the as-deposited film is exposed to an oxygen source such as water intermittently during the deposition process, as a post-deposit treatment, or a combination thereof, at least some or all of the nitrogen content in the film is converted to oxygen, providing a film selected from a silicon borocarboxyde film or a silicon borocarboxynitride film. Nitrogen in the film in its deposited state is released as one or more nitrogen-containing byproducts, such as ammonia or amine groups.

[0026] In one embodiment, a composition for forming a film containing silicon and boron comprises (a) at least one precursor compound having one Si-CB bond, selected from the group consisting of (trichlorosilyl)(dichloroboryl)methane, 1-(trichlorosilyl)-1-(dichloroboryl)ethane, 2-(trichlorosilyl)-2-(dichloroboryl)propane, and (dichloromethylsilyl)(dichloroboryl)methane, and (b) at least one solvent. In certain embodiments of the compositions described herein, exemplary solvents may include, but are not limited to, ethers, tertiary amines, alkyl hydrocarbons, aromatic hydrocarbons, tertiary amino ethers, siloxanes, and combinations thereof. In certain embodiments, the difference between the boiling point of the compound having one Si-CB bond and the boiling point of the solvent is 40°C or less. The weight percentage of the precursor compound in the solvent can vary within the range of 1% to 99% by weight, or 10% to 90% by weight, or 20% to 80% by weight, or 30% to 70% by weight, or 40% to 60% by weight, or 50% by weight. In some embodiments, the composition can be delivered via direct liquid injection into a reactor chamber for a silicon and boron-containing membrane using conventional direct liquid injection apparatus and methods.

[0027] In one embodiment of the method described herein, a silicon and boron-containing film having a boron content in the range of 10 at% to 45 at% is deposited using ALD or an ALD-like process and a hydrogen-containing plasma to improve film properties. In this embodiment, the method is a. Placing one or more substrates containing surface features into an ALD reactor, b. The reactor is heated to one or more temperatures in the range from ambient temperature to approximately 700°C, and optionally the reactor is maintained at a pressure of 100 torr or less. c. Introducing at least one precursor having one Si-CB bond, selected from the group consisting of (trichlorosilyl)(dichloroboryl)methane, 1-(trichlorosilyl)-1-(dichloroboryl)ethane, 2-(trichlorosilyl)-2-(dichloroboryl)propane, and (dichloromethylsilyl)(dichloroboryl)methane, into the reactor. d. Purging with an inert gas to remove unreacted precursors, e. Supplying a nitrogen source to the reactor and reacting it with the precursor to form a silicon borocarbonnitride film or a silicon borocarboxynitride film, f. Purge with an inert gas to remove reaction by-products, g. Repeat steps c through f to obtain a silicon borocarbonnitride film or silicon borocarboxynitride film of the desired thickness. h. Optionally, a silicon borocarbonitride membrane or silicon borocarboxynitride membrane is treated with an oxygen source at one or more temperatures ranging from ambient temperature to 1000°C, or in the range of approximately 100°C to approximately 400°C, to convert it to silicon borocarbonitride or silicon borocarboxynitride in situ or in another chamber. i. To provide a post-deposition treatment for a film containing silicon and boron, which involves exposing the film to a hydrogen-containing plasma to improve its film properties and improve at least one of its film properties. j. Optionally, the film containing silicon and boron may be post-treated by spike annealing at a temperature of 400°C to 1000°C or by using an ultraviolet light source. This includes the following. In this embodiment or other embodiments, the ultraviolet exposure step can be performed either during film formation or after film formation is complete. In one embodiment, the substrate includes at least one feature portion, the feature portion including a pattern trench with an aspect ratio of 1:9 and an opening of 180 nm. In one embodiment, the film containing silicon and boron is a silicon borocarbonnitride. In other embodiments, the film containing silicon and boron is a silicon borocarbonnitride and / or a silicon borocarboxynitride.

[0028] In yet another embodiment of the method described herein, a film containing silicon and boron is formed using a thermal ALD process with a catalyst containing ammonia or an organic amine. In this embodiment, the method is a. Placing one or more substrates containing surface features into an ALD reactor, b. The reactor is heated to one or more temperatures within a range of approximately 150°C or less from the ambient temperature, and optionally the reactor is maintained at a pressure of 100 torr or less. c. Introducing into the reactor at least one precursor having one Si-CB bond selected from the group consisting of (trichlorosilyl)(dichloroboryl)methane, 1-(trichlorosilyl)-1-(dichloroboryl)ethane, 2-(trichlorosilyl)-2-(dichloroboryl)propane, and (dichloromethylsilyl)(dichloroboryl)methane, and optionally a catalyst. d. Purge the reactor with an inert gas, e. Supplying an oxygen source to the reactor to react with the precursor and catalyst, thereby forming a film containing silicon and boron, f. Purge the reactor with an inert gas to remove reaction by-products, g. Repeat steps c through f to obtain a film containing silicon and boron to the desired thickness. h. To provide a post-deposition treatment for a treated film containing silicon and boron, which involves exposing the treated film to a hydrogen-containing plasma to improve at least one of the film properties. i. Optionally, the film containing silicon and boron may be post-processed by spike annealing at a temperature of 400°C to 1000°C or by using an ultraviolet light source. This includes the following. In this embodiment or other embodiments, the ultraviolet exposure step can be performed either during film formation or after film formation is complete.

[0029] In this embodiment or other embodiments, the catalyst is selected from Lewis bases such as pyridine, piperazine, ammonia, triethylamine, or other organic amines. The amount of Lewis base vapor is at least one equivalent of the amount of precursor vapor during step c. The oxygen source is water vapor. In some embodiments, the silicon and boron-containing film is silicon borocarboxylate. In other embodiments, the silicon and boron-containing film is silicon boroxide, as the oxygen source may remove all carbon from the silicon and boron-containing film in the deposited state during post-deposition treatment.

[0030] In certain embodiments, the resulting film containing silicon and boron is exposed to an organoaminosilane or chlorosilane having Si-Me or Si-H or both before being exposed to hydrogen plasma treatment to form a hydrophobic thin layer. Suitable organicaminosilanes include diethylaminotrimethylsilane, dimethylaminotrimethylsilane, ethylmethylaminotrimethylsilane, t-butylaminotrimethylsilane, isopropylaminotrimethylsilane, diisopropylaminotrimethylsilane, pyrrolidinotrimethylsilane, diethylaminodimethylsilane, dimethylaminodimethylsilane, ethylmethylaminodimethylsilane, t-butylaminodimethylsilane, isopropylaminodimethylsilane, diisopropylaminodimethylsilane, pyrrolidinodimethylsilane, bis(diethylamino)dimethylsilane, bis(dimethylamino)dimethylsilane, bis(ethylmethylamino)dimethylsilane, bis(diisopropylamino)dimethylsilane, bis(isopropylamino)dimethylsilane, bis(tert-butylamino)dimethylsilane, dipyrrolidinodi Examples include, but are not limited to, methylsilane, bis(diethylamino)diethylsilane, bis(diethylamino)methylvinylsilane, bis(dimethylamino)methylvinylsilane, bis(ethylmethylamino)methylvinylsilane, bis(diisopropylamino)methylvinylsilane, bis(isopropylamino)methylvinylsilane, bis(tert-butylamino)methylvinylsilane, dipyrrolidinomethylvinylsilane, 2,6-dimethylpiperidinomethylsilane, 2,6-dimethylpiperidinodimethylsilane, 2,6-dimethylpiperidinotrimethylsilane, tris(dimethylamino)phenylsilane, tris(dimethylamino)methylsilane, diisopropylaminosilane, di-sec-butylaminosilane, chlorodimethylsilane, chlorotrimethylsilane, dichloromethylsilane, and dichlorodimethylsilane.

[0031] In another embodiment, the resulting film containing silicon and boron is exposed to an alkoxysilane or cyclic alkoxysilane having Si-Me, Si-H, or both, before being exposed to hydrogen plasma treatment to form a hydrophobic thin layer. Suitable alkoxysilanes or cyclic alkoxysilanes include, but are not limited to, diethoxymethylsilane, dimethoxymethylsilane, diethoxydimethylsilane, dimethoxydimethylsilane, 2,4,6,8-tetramethylcyclotetrasiloxane, or octamethylcyclotetrasiloxane. While we do not wish to be bound by any theory or explanation, it is thought that the thin layer formed by the organic aminosilane or alkoxysilane or cyclic alkoxysilane transforms into dense carbon-doped silicon oxide during the plasma ashing process, further enhancing ashing resistance.

[0032] In another embodiment, a vessel for depositing a film containing silicon and boron contains one or more precursor compounds as described herein. In one particular embodiment, the vessel comprises at least one pressurized vessel (preferably stainless steel having a design as disclosed in U.S. Patents US7334595; US6077356; US5069244; and US5465766), the disclosures of which are incorporated herein by reference. The vessel may be made of glass (borosilicate glass or quartz glass) or type 316, 316L, 304 or 304L stainless steel alloy (UNS designations S31600, S31603, S30400, S30403) and is fitted with appropriate valves and accessories to deliver one or more precursors to a reactor for a CVD or ALD process. In this embodiment or other embodiments, the precursor is supplied to a pressurized container made of stainless steel, and the purity of the precursor is 98.0% by weight or more, or 99.0% by weight or more, or 99.5% by weight or more, suitable for semiconductor applications. The precursor compound is preferably Al 3+ Li + Ca 2+ Fe 2+ Fe 3+ Ni 2+ , Cr 3+It is substantially free of metal ions such as Al, Li, Ca, Fe, Ni, and Cr. As used herein, the term “substantially free” with respect to Al, Li, Ca, Fe, Ni, and Cr means less than about 5 ppm (by weight), preferably less than about 3 ppm, more preferably less than about 1 ppm, and most preferably less than about 0.1 ppm, as measured by ICP-MS. In certain embodiments, such a container may also have means for mixing the precursor with one or more additional precursors, if necessary. In these embodiments or other embodiments, the contents of the container may be pre-mixed with additional precursors. Alternatively, the precursors and / or other precursors may be maintained in separate containers or in a single container having separation means for maintaining the precursors and other precursors separated during storage.

[0033] Films containing silicon and boron are deposited on at least the surface of a substrate, such as a semiconductor substrate. In the methods described herein, the substrate may consist of and / or be coated with a variety of materials known in the art, including films of silicon, e.g., crystalline silicon or amorphous silicon, silicon oxide, silicon nitride, amorphous carbon, silicon oxycarbide, silicon oxynitride, silicon carbide, germanium, germanium-doped silicon, boron-doped silicon, metals, e.g., copper, tungsten, aluminum, cobalt, nickel, tantalum, metal nitrides, e.g., titanium nitride, tantalum nitride, metal oxides, Group III / V metals, or metalloids such as GaAs, InP, GaP, GaN, and combinations thereof. These coatings may completely coat the semiconductor substrate, be multilayers of various materials, or be partially etched to expose the underlying material. The surface may also have a photoresist material exposed in a pattern and developed to partially coat the substrate. In certain embodiments, the semiconductor substrate includes at least one surface feature selected from the group consisting of pores, vias, trenches, and combinations thereof. Potential applications of silicon and boron-containing films include, but are not limited to, low-k spacers for FinFETs or nanosheets, and sacrificial hard masks for self-aligned patterning processes (such as SADP, SAQP, or SAOP).

[0034] A film deposition method used to form a film or coating containing silicon and boron is a film deposition process. Examples of film deposition processes suitable for the methods disclosed herein include, but are not limited to, chemical vapor deposition or atomic layer deposition processes. As used herein, the term “chemical vapor deposition process” refers to any process in which a substrate is exposed to one or more volatile precursors, which react and / or decompose on the substrate surface to produce a desired film. As used herein, the term “atomic layer deposition process” refers to a self-limiting (e.g., the amount of film material deposited in each reaction cycle is constant) and sequential surface chemistry that deposits a film of material on a substrate of various compositions. As used herein, the term “thermal atomic layer deposition process” refers to an atomic layer deposition process at a substrate temperature in the range of room temperature to 700°C, or 100°C to 650°C, or 200°C to 650°C, or 300°C to 600°C, without the use of in situ or remote plasma. In other embodiments, the precursors described herein can be used, for example, in low-temperature film deposition when the catalyst is used at temperatures in the range of about 20°C to about 150°C, or about 50°C to about 150°C. While the precursors, reagents, and sources used herein may be described as “gaseous,” the precursors may be liquid or solid and are understood to be transported to the reactor by direct vaporization, bubbling, or sublimation, with or without an inert gas. In some cases, the vaporized precursor passes through a plasma generator.

[0035] In one embodiment, a film containing silicon and boron is deposited using an ALD process. In another embodiment, a film containing silicon and boron is deposited using a CCVD process. In a further embodiment, a film containing silicon and boron is deposited using a thermal ALD process. As used herein, the term “reactor” includes, but is not limited to, a reaction chamber or a deposition chamber.

[0036] In certain embodiments, the methods disclosed herein avoid preliminary reactions of precursors by using ALD or CCVD methods to separate precursors before and / or during introduction into the reactor. In connection with this, silicon and boron-containing films are deposited using deposition techniques such as ALD or CCVD processes. In one embodiment, the film is deposited via the ALD process in a typical single-wafer ALD reactor, semi-batch ALD reactor, or batch furnace ALD reactor by alternately exposing the substrate surface to one or more silicon-containing precursors and boron-containing precursors, an oxygen source, a nitrogen-containing source, or other precursors or reagents. Film growth proceeds by self-limiting control of the surface reaction, the pulse length of each precursor or reagent, and the deposition temperature. However, film growth stops when the substrate surface becomes saturated. In another embodiment, each reagent, including precursors and reactive gases, is exposed to the substrate by moving or rotating the substrate to different sections of the reactor, each section being separated by an inert gas curtain, i.e., a space ALD reactor or roll-to-roll ALD reactor.

[0037] Depending on the film formation method, in certain embodiments, the silicon precursor described herein, and optionally other silicon-containing precursors and boron-containing precursors, can be introduced into the reactor in a predetermined molar volume, or from about 0.1 micromoles to about 1000 micromoles. In this embodiment or other embodiments, the precursors may be introduced into the reactor for a predetermined time. In certain embodiments, the time is in the range of about 0.001 seconds to about 500 seconds.

[0038] In certain embodiments, films containing silicon and boron deposited using the method herein are formed in the presence of an oxygen source, a reagent, or an oxygen-containing precursor, i.e., a catalyst combined with water vapor. The oxygen source can be introduced into the reactor in the form of at least one oxygen source and / or can be incidentally present in other precursors used in the film deposition process. Suitable oxygen source gases may include, for example, water (H2O) (e.g., deionized water, purified water, distilled water, water vapor, water vapor plasma, oxygen-containing water, air, water and other organic liquids), oxygen (O2), oxygen plasma, ozone (O3), nitric oxide (NO), nitrogen dioxide (NO2), carbon monoxide (CO), water plasma, water and argon plasma, hydrogen peroxide, hydrogen-containing compositions, hydrogen and oxygen-containing compositions, carbon dioxide (CO2), air, and combinations thereof. In certain embodiments, the oxygen source comprises an oxygen source gas introduced into the reactor at a flow rate in the range of about 1 cubic centimeter (sccm) to about 10,000 sccm or about 1 sccm to about 1,000 sccm. The oxygen source can be introduced over a time range of about 0.1 seconds to about 100 seconds. The catalyst is selected from Lewis bases such as pyridine, piperazine, trimethylamine, tert-butylamine, diethylamine, trimethylamine, ethylenediamine, ammonia, or other organic amines.

[0039] In embodiments in which a film containing silicon and boron is deposited by ALD or a circulating CVD process, the precursor pulse may have a pulse duration greater than 0.01 seconds, the nitrogen source or oxygen source may have a pulse duration less than 0.01 seconds, and the water pulse may have a pulse duration less than 0.01 seconds.

[0040] In certain embodiments, a nitrogen source or an oxygen source is continuously supplied into the reactor while the precursor pulse and plasma are introduced sequentially. The precursor pulse may have a pulse duration greater than 0.01 seconds, and the plasma duration may be in the range of 0.01 seconds to 100 seconds.

[0041] In certain embodiments, the film comprises silicon, nitrogen, and boron. In these embodiments, the film deposited using the method described herein is formed in the presence of a nitrogen-containing source. The nitrogen-containing source may be introduced into the reactor in the form of at least one nitrogen source and / or may be incidentally present in other precursors used in the film deposition process.

[0042] Suitable nitrogen-containing or nitrogen source gases may include, for example, ammonia, hydrazine, monoalkylhydrazine, symmetric or asymmetric dialkylhydrazine, organic amines such as methylamine, ethylamine, ethylenediamine, ethanolamine, piperazine, N,N'-dimethylethylenediamine, imidazolidine, and cyclotrimethylenetriamine, as well as combinations thereof.

[0043] In certain embodiments, the nitrogen source is introduced into the reactor at a flow rate in the range of about 1 cubic centimeter (sccm) to about 10,000 sccm or about 1 sccm to about 1,000 sccm. The nitrogen source can be introduced for a time in the range of about 0.1 seconds to about 100 seconds. In embodiments in which the film is deposited by an ALD or circulating CVD process using both a nitrogen source and an oxygen source, the precursor pulse may have a pulse duration greater than 0.01 seconds, the nitrogen source may have a pulse duration less than 0.01 seconds, and the water pulse may have a pulse duration less than 0.01 seconds. In yet another embodiment, the purge duration between pulses is as low as 0 seconds, or the pulses are pulsed continuously without purging in between.

[0044] The film deposition methods disclosed herein may include one or more purge gases. The purge gas used to purge unconsumed reactants and / or reaction by-products is an inert gas that does not react with the precursor. Examples of purge gases include, but are not limited to, argon (Ar), nitrogen (N2), helium (He), neon, hydrogen (H2), and combinations thereof. In certain embodiments, a purge gas such as Ar is supplied into the reactor at a flow rate in the range of about 10 sccm to about 10,000 sccm for a period of about 0.1 seconds to about 1,000 seconds, thereby purging unreacted material and any by-products that may remain in the reactor.

[0045] Each step of supplying the precursor, oxygen source, nitrogen-containing source, and / or other precursors, source gases, and / or reagents can be carried out by varying the supply time to change the stoichiometric composition of the resulting membrane.

[0046] Energy is applied to at least one of a precursor, a nitrogen source or nitrogen-containing source, an oxygen source, a reducing agent, another precursor, or a combination thereof to induce a reaction and form a film or coating on a substrate. Such energy can be supplied by, but is not limited to, heat, plasma, pulsed plasma, helicon plasma, high-density plasma, inductively coupled plasma, X-rays, electron beams, photons, remote plasma methods, and combinations thereof.

[0047] In certain embodiments, a secondary RF frequency source can be used to modify the plasma properties on the substrate surface. In embodiments in which the film deposition involves plasma, the plasma generation process may include a direct plasma generation process in which the plasma is generated directly within the reactor, or alternatively, a remote plasma generation process in which the plasma is generated outside the reactor and supplied into the reactor.

[0048] Silicon precursors and / or other silicon-containing precursors and boron-containing precursors can be delivered to reaction chambers such as CVD or ALD reactors by various methods. In one embodiment, a liquid delivery system can be utilized. In an alternative embodiment, a process unit combining liquid delivery and flash vaporization, such as a turbo vaporizer from MSP, Shoreview, Minnesota, can be employed to supply low-volatility materials by volume, thereby providing reproducible delivery and film formation without thermal decomposition of the precursor. In liquid delivery formulations, the precursors described herein may be delivered in neat liquid form, or alternatively, may be employed in solvent formulations or compositions containing them. Thus, in certain embodiments, the precursor formulation may contain solvent components with appropriate properties that may be desirable and advantageous in a given end-use application for forming films on a substrate.

[0049] In this embodiment or other embodiment, it is understood that the steps of the method described herein may be performed in various orders, sequentially or simultaneously (for example, between at least some of the steps of another step), or in any combination thereof. Each step of supplying the precursor and nitrogen-containing feedstock gas can be carried out by varying the duration of time they are supplied in order to change the stoichiometric composition of the resulting silicon and boron-containing film.

[0050] In further embodiments of the methods described herein, the film or the film in a deposited state is subjected to a processing step. The processing step can be carried out during at least part of the film deposition process, after the film deposition process, and in combination thereof. Exemplary processing steps include, but are not limited to, high-temperature thermal annealing, plasma treatment, ultraviolet (UV) light treatment, laser treatment, electron beam treatment, and combinations thereof, which affect one or more properties of the film. Films deposited using silicon precursors having one or two Si-CB bonds as described herein have improved properties, but are not limited to, films deposited using previously disclosed silicon precursors under the same conditions, such as a lower wet etching rate than the film before the processing step, or a higher density than the density before the processing step. In a particular embodiment, the film in a deposited state is intermittently processed during the film deposition process. These intermittent or intermediate deposition processes can be performed after a certain number of ALD cycles, for example, after each ALD cycle, but not limited to every 1(1) ALD cycle, 2(2) ALD cycle, 5(5) ALD cycle, or 10(10) or more ALD cycles.

[0051] In embodiments in which the film is treated in a high-temperature annealing process, the annealing temperature is at least 100°C higher than the film deposition temperature. In this embodiment or other embodiments, the annealing temperature is in the range of about 400°C to about 1000°C. In this embodiment or other embodiments, the annealing process can be carried out in a vacuum (less than 760 Torr), an inert environment, or an oxygen-containing environment (such as H2O, N2O, NO2, or O2).

[0052] In embodiments in which the film is treated with ultraviolet light, the film is exposed to broadband ultraviolet light, or alternatively, to an ultraviolet light source having a wavelength in the range of approximately 150 nanometers (nm) to approximately 400 nm. In one particular embodiment, after reaching a desired film thickness, the deposited film is exposed to ultraviolet light in a chamber different from the deposition chamber.

[0053] In embodiments where the film is treated with plasma, a passivation layer, such as SiO2 or carbon-doped SiO2, is deposited to prevent chlorine and nitrogen contamination from penetrating the film during subsequent plasma treatment. The passivation layer can be deposited using atomic layer deposition or cyclic chemical vapor deposition.

[0054] In embodiments where the film is treated with plasma, the plasma source is selected from the group consisting of hydrogen plasma, plasma containing hydrogen and helium, and plasma containing hydrogen and argon. Hydrogen plasma reduces the dielectric constant of the film and enhances its resistance to subsequent plasma ashing processes without significantly changing the boron content in the bulk.

[0055] Throughout this specification, the term “ALD or ALD-like” refers to a process that includes, but is not limited to, the following: a) sequentially introducing each reagent, including precursors and reactive gases, into a reactor such as a single-wafer ALD reactor, a semi-batch ALD reactor, or a batch furnace ALD reactor; and b) exposing each reagent, including precursors and reactive gases, to a substrate by moving or rotating the substrate to different sections of the reactor, with each section being separated by an inert gas curtain, i.e., a space ALD reactor or a roll-to-roll ALD reactor.

[0056] Throughout this specification, the term "ashing" refers to the process of removing a photoresist or carbon hard mask in a semiconductor manufacturing process using a plasma containing an oxygen source, such as an O2 / inert gas plasma, O2 plasma, CO2 plasma, CO plasma, H2 / O2 plasma, or a combination thereof.

[0057] Throughout this specification, the term "damage resistance" refers to the film properties after the oxygen ashing process. Good or high damage resistance is defined as the following film properties after oxygen ashing: the dielectric constant of the film is less than 4.5; the boron content of the bulk (film depth greater than 50 Å) is within 5 at%, the same as before ashing; and the film is damaged less than 50 Å, as observed by the difference in dilute HF etching rates between the near surface (depth less than 50 Å) and the bulk (depth greater than 50 Å).

[0058] Throughout this specification, the term "alkyl hydrocarbon" refers to a linear or branched C1-C1 hydrocarbon. 20 Hydrocarbons, cyclic C6-C 20 This refers to hydrocarbons. Examples of hydrocarbons include, but are not limited to, heptane, octane, nonane, decane, dodecane, cyclooctane, cyclononane, and cyclodecane.

[0059] Throughout this specification, the term "aromatic hydrocarbon" refers to C6-C6 20 This refers to aromatic hydrocarbons. Examples of aromatic hydrocarbons include toluene and mesitylene, but are not limited to these.

[0060] Throughout this specification, the term “catalyst” refers to a gas-phase Lewis base capable of catalyzing surface reactions between hydroxyl groups and Si-Cl bonds in a thermal ALD process. Examples of catalysts include, but are not limited to, cyclic amine gases such as aminopyridine, picoline, lutidine, piperazine, piperidine, pyridine, or organic amine gases such as methylamine, dimethylamine, trimethylamine, ethylamine, diethylamine, triethylamine, propylamine, isopropylamine, dipropylamine, diisopropylamine, and tert-butylamine, at least one of these.

[0061] Throughout this specification, the term "organic amine" refers to C1-C 20 Hydrocarbons, cyclic C6-C 20This refers to primary, secondary, and tertiary amines that possess hydrocarbons. Examples of organic amines include, but are not limited to, methylamine, dimethylamine, trimethylamine, ethylamine, diethylamine, triethylamine, propylamine, isopropylamine, dipropylamine, diisopropylamine, and tert-butylamine.

[0062] Throughout this specification, the term "siloxane" means a bond consisting of at least one Si-O-Si bond and C4-C 20 This refers to linear, branched, or cyclic liquid compounds containing carbon atoms. Examples of siloxanes include, but are not limited to, tetramethyldisiloxane, hexamethyldisiloxane (HMDSO), 1,1,1,3,3,5,5,5-octamethyltrisiloxane, and octamethylcyclotetrasiloxane (OMCTS).

[0063] Throughout this specification, the term “stepped coverage” as used herein is defined as the ratio of two thicknesses of a deposited film on a structured substrate or feature substrate having either or both vias and trenches, where the lower stepped coverage is a ratio (%), i.e., the lower thickness of the feature divided by the upper thickness of the feature, and the middle stepped coverage is a ratio (%), i.e., the sidewall thickness of the feature divided by the upper thickness of the feature. Films deposited using the method described herein exhibit a stepped coverage of about 80% or more, or about 90% or more, indicating that the film is conformal.

[0064] Throughout this specification, the term “inert gas” refers to a nonreactive gas selected from the group consisting of nitrogen, helium, argon, neon, and combinations thereof. Inert gases can be used to supply silicon precursors, purge reactors, or maintain reactor chamber pressure.

[0065] Throughout this specification, the term “silicon and boron-containing film” refers to a film selected from the group consisting of silicon borocarboxylate, silicon borocarbonnitride, silicon boroside, and silicon borocarboxynitride. A silicon boroside refers to a film having more than 1 at% silicon, more than 1 at% boron, and more than 1 at% oxygen, with other elements present in less than 1 at%. A silicon borocarboxylate refers to a film having more than 1 at% silicon, more than 1 at% boron, more than 1 at% carbon, and more than 1 at% oxygen, with other elements present in less than 1 at%. A silicon borocarbonnitride is a film having more than 1 at% silicon, more than 1 at% boron, more than 1 at% carbon, and more than 1 at% nitrogen, with other elements present in less than 1 at%. Silicon borocarboxynitrides refer to films containing more than 1 at% silicon, more than 1 at% boron, more than 1 at% carbon, more than 1 at% oxygen, and more than 1 at% nitrogen, with other elements present in amounts less than 1 at%.

[0066] The following examples illustrate specific aspects of the immediate invention and do not limit the scope of the attached claims. [Examples]

[0067] General film deposition Using a precursor and ammonia as the nitrogen source, film deposition was performed in a screening atomic layer deposition (ALD) reactor. The steps and process conditions of the ALD cycle are shown in Table 2 below.

[0068] [Table 1]

[0069] During film deposition, steps 3 to 14 were repeated for up to 2000 cycles to obtain the desired thickness of the carbon-containing film. The refractive index and film thickness were measured directly at 632.8 nm after deposition using an ellipsometer. To eliminate the influence of adventitious carbon, the composition of the bulk film was characterized using X-ray photoelectron spectroscopy (XPS) at a depth of several nanometers (approximately 5 nm) from the surface.

[0070] Oxygen ashing was performed using a commercially available ashing machine (PVA Tepla Metroline 4L). The process parameters were as follows: 100 sccm helium, 300 sccm oxygen, 600 torr pressure, and plasma power set to 200 W. Damage depth was measured by dilute HF etching.

[0071] The wet etching rate process was carried out under two different concentrations of dilute hydrofluoric acid (dHF), with a ratio of 49% HF to DI water of 1:99. During the process, the thermal silicon oxide film was simultaneously etched to ensure consistency of the etching solution.

[0072] To form a metal-insulator-semiconductor capacitor (MISCAP) structure, metal electrodes were deposited on a film, and the dielectric constant (k) and leakage current were measured. The leakage current density was reported at a bias voltage of 1 MV / cm.

[0073] Example 1: A film containing silicon and boron was formed using 1-(trichlorosilyl)-1-(dichloroboryl)ethane and ammonia.

[0074] Using 1-(trichlorosilyl)-1-(dichloroboryl)ethane and ammonia, silicon and boron-containing films were deposited in an ALD screening reactor at temperatures between 300°C and 600°C. Process parameters and the ALD cycle are shown in Table 2. The total exposure to precursors was between 2 Torr.s and 3 Torr.s, and the total exposure to NH3 was 125 Torr.s. After film deposition, the films were exposed to ambient trace moisture for at least 24 hours before measurement.

[0075] [Table 2]

[0076] The oxygen present in the film was thought to be due to exposure to air after film formation. This demonstrated the concept of the possibility of adjusting the film composition by exposing the film to an oxidizing agent to convert silicon boronoxide to silicon boronoxynitride.

[0077] The film deposited at 600°C had a k-value of 4.1 and a leakage current density of 9E-8A / cm². 2 The etching rate of the film at dilute HF is 60% lower than that of thermal silicon oxide at dilute HF.

[0078] As demonstrated in Example 1, a film deposited at 600°C was deposited on a pattern structure with an aspect ratio of 1.9. The structural opening was 130 nm. The film thickness at different locations in the trench was analyzed using cross-sectional TEM. As shown in Table 4, the film showed a fit of over 97%.

[0079] [Table 3]

[0080] Example 2: A film containing silicon and boron, formed using 1-(trichlorosilyl)-1-(dichloroboryl)ethane, ammonia, and water vapor.

[0081] Silicon was deposited on the boron-containing film using -(trichlorosilyl)-1-(dichloroboryl)ethane, ammonia, and water vapor according to the procedure described in Table 5.

[0082] [Table 4]

[0083] Steps 3 through 16 were repeated multiple times to obtain the desired film thickness.

[0084] [Table 5]

[0085] Table 6 summarizes the GPC and film composition of the deposited films. The film composition can be adjusted by changing the deposition temperature and co-reactants.

[0086] Example 3: Silicon and boron-containing film formed using (trichlorosilyl)(dichloroboryl)methane and ammonia.

[0087] Using (trichlorosilyl)(dichloroboryl)methane and ammonia, silicon and boron-containing films were deposited according to the procedure outlined in Table 7.

[0088] [Table 6]

[0089] Steps 3 through 13 were repeated multiple times to obtain the desired film thickness.

[0090] [Table 7]

[0091] Table 8 summarizes the GPC and film composition. The film composition can be adjusted by changing the deposition temperature.

[0092] The film deposited at 600°C had a k-value of 4.2 and a leakage current density of 1.0E-8A / cm² at a bias voltage of 1MV / cm². 2 The dilute HF wet etching rate of the 600°C film was 60% lower than that of the dilute HF wet etching rate of the thermal silicon oxide film, demonstrating that silicon and boron-containing films are superior to thermal silicon oxide films.

[0093] Example 4: A film containing silicon and boron, formed using (trichlorosilyl)(dichloroboryl)methane, ammonia, and water vapor.

[0094] Using (trichlorosilyl)(dichloroboryl)methane, ammonia, and water vapor, silicon and boron-containing films were formed using the process described in Table 9.

[0095] [Table 8]

[0096] Steps 3 through 16 were repeated multiple times to obtain the desired film thickness.

[0097] [Table 9]

[0098] Table 10 summarizes the GPC and film composition. The film composition can be adjusted by changing the process deposition temperature.

[0099] The film deposited at 600°C had a k-value of 4.5 and a leakage current density of 1.0E-8A / cm² at a bias voltage of 1MV / cm². 2 The etching rate of a thin film deposited at 600°C using dilute HF etching is 30% lower than that of thermal silicon oxide using dilute HF etching.

Claims

1. A composition for ALD film formation of films containing silicon and boron, (a) At least one precursor compound having one Si-C-B bond, selected from the group consisting of trichlorosilyl(dichloroboryl)methane, 1-(trichlorosilyl)-1-(dichloroboryl)ethane, 2-(trichlorosilyl)-2-(dichloroboryl)propane, and (dichloromethylsilyl)(dichloroboryl)methane, (b) at least one solvent, A composition containing the following:

2. The composition according to claim 1, wherein the solvent comprises at least one selected from the group consisting of ethers, tertiary amines, siloxanes, alkyl hydrocarbons, aromatic hydrocarbons, and tertiary amino ethers.

3. The composition according to claim 1, wherein the difference between the boiling point of the at least one precursor and the boiling point of the at least one solvent is about 40°C or less.

4. The composition according to claim 1, further comprising less than 5 ppm of at least one metal ion selected from the group consisting of Al ions, Li ions, Ca ions, Fe ions, Ni ions, and Cr ions, as measured by ICP-MS.

5. The composition according to claim 1, wherein the at least one solvent comprises at least one selected from the group consisting of heptane, octane, nonane, decane, dodecane, cyclooctane, cyclononane, cyclodecane, toluene, and mesitylene.

6. A method for forming a silicon and boron-containing film by an ALD process, wherein the boron content measured by XPS is in the range of 10 at% to 40 at%, and the method is as follows: a) Placing one or more substrates including surface features into an ALD reactor, b) Heating the reactor to one or more temperatures in the range from ambient temperature to approximately 700°C, and optionally maintaining the reactor at a pressure of 100 torr or less, c) Introducing at least one precursor having a Si-C-B bond into the reactor, d) Purging the reactor using an inert gas, e) Supplying a nitrogen source or an oxygen source to the reactor and reacting it with at least one of the precursors to form a film containing silicon and boron, f) Purging the reactor with an inert gas, g) Repeating steps c through f to obtain a film containing silicon and boron to a desired thickness, h) Optionally, the film containing silicon and boron is treated with an oxygen source at one or more temperatures in the range of approximately ambient temperature to about 1000°C, or in the range of about 100°C to about 400°C, to convert the film containing silicon and boron into a silicon borocarboxynitride film or a silicon boroxynitride film. i) Optionally, expose the film containing silicon and boron to a plasma containing hydrogen, Methods that include...

7. A film containing silicon and boron, formed according to the method of claim 6, having a k of about 6 or less and a boron content of at least about 10 at% or more and about 45 at% or less.

8. A film comprising silicon and boron, formed according to the method of claim 6, having an etching rate at least 30% lower than the etching rate of thermal silicon oxide.

9. A film comprising silicon and boron, formed according to the method of claim 6, having an etching rate at least 50% lower than the etching rate of thermal silicon oxide.

10. A film comprising silicon and boron, formed according to the method of claim 6, having an etching rate at least 70% lower than the etching rate of thermal silicon oxide.

11. A film comprising silicon and boron, formed according to the method of claim 6, having an etching rate at least 90% lower than the etching rate of thermal silicon oxide.

12. The method according to claim 6, wherein the at least one precursor is selected from the group consisting of (trichlorosilyl)(dichloroboryl)methane, 1-(trichlorosilyl)-1-(dichloroboryl)ethane, 2-(trichlorosilyl)-2-(dichloroboryl)propane, and (dichloromethylsilyl)(dichloroboryl)methane.

13. A stainless steel container for containing the composition described in claim 1.

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