Silicon-based thin films using N-alkyl-substituted perhydridocyclotrisilazanes

Abstract

A low- to medium-temperature vapor deposition process is provided for the deposition of silicon-based thin films, such as silicon nitride films, silicon carbonitride films, silicon oxide films, and silicon films. The process includes, in one cycle, heating a substrate to a predetermined temperature, providing a precursor comprising an N-alkyl-substituted perhydridocyclotrisilazane in the vapor phase to a reaction region containing the substrate, forming a monolayer of the precursor by adsorption onto the substrate surface, and exposing the adsorbed monolayer on the substrate in the reaction region to a remote or direct soft plasma of a co-reactant. The adsorbed monolayer of the precursor reacts with the soft plasma and undergoes conversion into discrete atomic or molecular layers of the silicon-based thin film via dissociation and / or decomposition due to or enabled by the substrate surface-induced treatment. The cycle is then repeated to form a silicon-based thin film of a desired thickness.

Description

[Technical Field]

[0001] (Cross-reference of related applications) This application claims priority to U.S. Provisional Patent Application No. 63 / 030684, filed on 27 May 2020, the disclosure of which is incorporated herein by reference. [Background technology]

[0002] Silicon Nitride (SiN x Interest in the research, development, and manufacturing of Si-based thin films, such as silicon dioxide (Si) and silicon oxide (SiO2), is growing at an unprecedented intensity, not only due to the need for its historically expanding applicability in the ever-evolving integrated circuit (IC) and solar cell industries, but also due to its potential use in numerous new applications. These new applications include, for example, host matrices for Si nanocrystals (Si-NC) and quantum dots (QD) for photoluminescence applications, waveguides in nonlinear frequency combs for sensors and photonic elements for telecommunications, tunable light-emitting films for Si-based light-emitting diodes (LEDs) in Si-based monolithic optoelectronic integration, passivation / encapsulation nanostructures at interfaces with gallium arsenide (GaAs) for compound semiconductor devices, and base platforms for integration with biomaterials for biochemical and medical applications.

[0003] The great appeal of Si-based thin films lies in their highly promising combination of physical, chemical, mechanical, electrical, and optoelectronic properties, which has made them one of the most commonly used materials across a wide variety of industries. Many of these industries share the same evolutionary drive in terms of the trend toward the integration of smaller, heterogeneous device structures using thermally and / or chemically sensitive substrates. As a result, research and development activities have focused on the development and optimization of low-temperature deposition processes such as direct and remote plasma-enhanced chemical vapor deposition (PE-CVD), laser-assisted CVD, mirror plasma-enhanced chemical vapor deposition (MPECVD), porous hollow cathode radio frequency (RF) PECVD, and direct, remote, and glow discharge plasma-enhanced atomic layer deposition.

[0004] Despite these diligent research and development efforts, significant challenges must still be overcome to enable the scalability of Si-based thin films for heterogeneous device applications. One major commonality between PE-CVD and PE-ALD processes is the use of silanes (SiH4) and silane-type precursors. Numerous documented problems associated with the use of this chemical reaction include their spontaneous combustion, high thermal budget, and high levels of hydrogen uptake. Furthermore, PE-ALD processes using silane-type silicon sources require substrate surface pretreatment, adding complexity and cost due to substrate surface adsorption and nucleation issues. Moreover, the resulting films are composed of highly variable concentrations of silicon, oxygen, and nitrogen due to high levels of contaminants, and / or compositional gradients from Si to N and Si to O between the film interface, bulk, and surface regions.

[0005] For these reasons, we aim to maximize processing efficiency and productivity by minimizing the number and complexity of substrate surface pretreatment steps, while also minimizing silicon nitride (SiN x ) and silicon oxide (SiO2) and SiC x N yIt is desirable to provide a thin-film deposition technology that overcomes the aforementioned shortcomings of conventional deposition technologies by depositing high-quality Si-based thin films, such as those alloys, at low temperatures. [Overview of the Initiative]

[0006] In one embodiment, the present disclosure relates to a method for depositing a silicon nitride thin film on a substrate in a reaction region of a deposition chamber, the method comprising the steps of: heating the substrate to a temperature of about 200°C to about 650°C in one cycle; maintaining the substrate at about 200°C to about 650°C; providing a precursor containing an N-alkyl-substituted perhydride cyclotrisilazane in vapor phase to a reaction region including the substrate together with a carrier gas and / or under vacuum; forming a monolayer film of the N-alkyl-substituted perhydride cyclotrisilazane by adsorption onto the surface of the substrate; and exposing the adsorbed monolayer film on the substrate in the reaction region to a soft plasma containing nitrogen-containing reactants, wherein the adsorbed monolayer film of the N-alkyl-substituted perhydride cyclotrisilazane reacts with the soft plasma and undergoes conversion to discrete atoms or molecular layers of silicon nitride thin film via dissociation and / or decomposition caused by or enabled by the substrate surface-induced treatment, and byproducts of the conversion are removed from the reaction region via a purging step with an inert gas and / or vacuum.

[0007] In a second embodiment, a method for depositing a silicon oxide thin film on a substrate in a reaction region of a deposition chamber comprises, in one cycle, the steps of: heating the substrate to a temperature of about 200°C to about 650°C; maintaining the substrate at about 200°C to about 650°C; providing a precursor containing an N-alkyl-substituted perhydride cyclotrisilazane in vapor phase to the reaction region including the substrate together with a carrier gas and / or under vacuum; forming a monolayer film of the N-alkyl-substituted perhydride cyclotrisilazane by adsorption onto the surface of the substrate; and exposing the adsorbed monolayer film on the substrate in the reaction region to an oxygen-containing reactant, either remotely or directly, a soft plasma, wherein the adsorbed N-alkyl-substituted perhydride cyclotrisilazane monolayer film reacts with the soft plasma and undergoes conversion to discrete atoms or molecular layers of the silicon oxide thin film via dissociation and / or decomposition resulting from or enabled by the substrate surface-induced treatment, and the by-products of the conversion are removed from the reaction region by an inert gas and / or under vacuum via a purging step.

[0008] In further embodiments, the Disclosure provides a method for depositing a silicon carbonitride thin film on a substrate in a reaction region of a deposition chamber, the method comprising the steps of: heating the substrate to a temperature of room temperature to about 200°C in one cycle; maintaining the substrate at room temperature to about 200°C; providing a precursor comprising an N-alkyl-substituted perhydride cyclotrisilazane in vapor phase together with a carrier gas and / or under vacuum to the reaction region including the substrate; forming a monolayer film of the N-alkyl-substituted perhydride cyclotrisilazane by adsorption onto the surface of the substrate; and exposing the adsorbed monolayer film on the substrate in the reaction region to a soft plasma of nitrogen-containing reactants, wherein the adsorbed monolayer film of the N-alkyl-substituted perhydride cyclotrisilazane reacts with the soft plasma and undergoes conversion to discrete atoms or molecular layers of the silicon carbonitride thin film via dissociation and / or decomposition resulting from or enabled by the substrate surface-induced treatment, and byproducts of the conversion are removed from the reaction region by an inert gas and / or under vacuum via a purging step.

[0009] In other embodiments, the Disclosure provides a method for depositing a silicon thin film on a substrate in a reaction region of a deposition chamber, the method comprising the steps of: heating the substrate to a temperature of about 200°C to about 650°C in one cycle; maintaining the substrate at about 200°C to about 650°C; providing a precursor comprising a vapor phase of N-alkyl-substituted perhydride cyclotrisilazane together with a carrier gas and / or under vacuum to a reaction region including the substrate; forming a monolayer film of N-alkyl-substituted perhydride cyclotrisilazane by adsorption onto the surface of the substrate; and exposing the adsorbed monolayer film on the substrate in the reaction region to a soft plasma of hydrogen-containing reactants, wherein the adsorbed monolayer film of N-alkyl-substituted perhydride cyclotrisilazane reacts with the soft plasma and undergoes conversion of the silicon thin film into discrete atoms or molecular layers via dissociation and / or decomposition resulting from or enabled by the substrate surface-induced treatment, and byproducts of the conversion are removed from the reaction region by an inert gas and / or vacuum via a purging step.

[0010] The following detailed description of preferred embodiments of the present invention will be better understood in conjunction with the accompanying drawings. For the purpose of illustrating the present invention, the drawings show currently preferred embodiments. However, it should be understood that the present invention is not limited to the exact arrangements and means shown in the drawings. [Brief explanation of the drawing]

[0011] [Figure 1] This graph shows TICZ experimental vapor pressure data and the fit of the Antoine equation over the range of 0.14 to 760 torr. [Figure 2] This is a schematic window diagram of the optimized SiNx processing for various substrate temperatures ranging from 50 to 350°C. [Figure 3] This graph shows real-time in-situ ellipsometry measurements of film thickness versus deposition time for substrate temperatures of 200°C at TICZ exposure times of 0.4 seconds, 1.0 seconds, 2.0 seconds, 3.0 seconds, and 5.0 seconds. [Figure 4]This graph shows real-time in-situ ellipsometry measurements of film thickness versus deposition time for substrate temperatures of 150, 175, 200, 225, 300, and 350°C. [Figure 5] This graph shows real-time in-situ ellipsometry measurements of film thickness versus deposition time during the first minute of SiNx processing. [Figure 6] This is an XPS profile of Zn, Si, N, C, and O concentrations versus penetration depth in a SiNx film deposited at 200°C. [Figure 7] This is an XPS profile of Zn, Si, N, C, and O concentrations versus penetration depth in a SiNx film deposited at 300°C. [Figure 8] This figure shows high-resolution XPS spectra of Si2p, N1s, C1s, and O1s bond energy pairs and penetration depths in a SiNx film deposited at 200°C. [Figure 9] This figure shows high-resolution XPS spectra of Si2p, N1s, C1s, and O1s bond energy pairs and penetration depths in a SiNx film deposited at 300°C. [Figure 10] This is the XPS depth profile of Zn, Si, N, C, and O concentrations for SiCxNy deposited at 50°C. [Figure 11] These are XPS depth profiles of Zn, Si, N, C, and O concentrations for SiCxNy deposited at 150°C. [Figure 12] This figure shows high-resolution XPS core-level spectra of Si2p, N1s, C1s, and O1s bond energy pairs and penetration depths in SiCxNy deposited at 50°C. [Figure 13] This figure shows high-resolution XPS core-level spectra of Si2p, N1s, C1s, and O1s bond energy pairs and penetration depths in SiCxNy deposited at 150°C. [Figure 14] This graph shows real-time, in-situ, angle-resolved ellipsometry measurements of SiCxNy film thickness versus deposition time for a substrate temperature of 150°C and TICZ pulse times of 0.1 seconds, 0.2 seconds, 0.4 seconds, and 0.8 seconds. [Figure 15] This graph shows real-time, in-situ, angle-resolved ellipsometry measurements of SiCxNy film thickness versus deposition time for substrate temperatures of 30, 60, 90, 120, 150, and 170°C. [Modes for carrying out the invention]

[0012] Aspects of this disclosure relate to low-to-medium temperature vapor phase growth treatment for depositing Si-based thin films on a substrate in the reaction region of a deposition chamber. The process, in one cycle, includes the steps of: heating the substrate to a desired temperature and maintaining the substrate at that temperature; providing a precursor containing an N-alkyl-substituted perhydride cyclotrisilazane in vapor phase to a reaction region including the substrate, together with a carrier gas and / or under vacuum; forming a monolayer film of the N-alkyl-substituted perhydride cyclotrisilazane by adsorption on the substrate surface; optionally removing unreacted perhydride cyclotrisilazane and its by-products from the reaction region using an inert gas via a purging step and / or vacuum; and exposing the adsorbed monolayer film on the substrate in the reaction region to a soft plasma indirectly or directly to other chemical species or co-reactants, wherein the adsorbed N-alkyl-substituted perhydride cyclotrisilazane monolayer film reacts with the soft plasma and undergoes conversion to discrete atoms or molecular layers of the Si-based thin film via dissociation and / or decomposition caused by or enabled by the substrate surface-induced treatment, and the by-products of the conversion are removed from the reaction region by an inert gas via a purging step and / or vacuum. A cycle is repeated multiple times as desired to form a Si-based thin film of a desired or predetermined thickness. As will be explained in detail below, the appropriate substrate temperature and soft plasma composition are determined by the desired chemical composition of the silicon-based thin film, such as silicon nitride, silicon carbonitride, silicon oxide, or silicon.

[0013] The term "thin film" is well understood in this field and can include films ranging in thickness from a few nanometers to a few microns. As mentioned above, its thickness is controlled by the number of cycles performed.

[0014] In some embodiments, the conversion from an adsorbed monolayer to a discrete atom or molecular layer may be assisted or enabled by energy transfer from an energy source such as a heated substrate. For example, surface-induced treatments such as energy transfer from the substrate (thermal exposure), remote or direct plasma application, oxidation and / or reduction may be used to initiate or accelerate the conversion from an adsorbed monolayer to a final deposited film.

[0015] The term "soft plasma" refers to a plasma-induced treatment that imparts minimal energy to a target film or substrate, causing little to no mechanical, chemical, physical, or electrical damage to the film or substrate. Similarly, soft plasma refers to a plasma-induced treatment that imparts energy to target molecules below the threshold for fracture, fragmentation, or decomposition of those molecules. Instead, soft plasma is preferably designed in combination with an additional thermal energy source on the substrate surface to provide sufficient activation energy to the precursor, enabling its controlled decomposition.

[0016] The process described here employs N-alkyl-substituted perhydride cyclotrisilazanes as the Si source precursor. Unlike perhydrogenated cyclic silazanes that have a methyl group attached to the N atom, these silazanes contain alkyl radicals with at least two carbon atoms attached to each N atom, and the removal of alkyl substitution leads to low-to-medium temperature SiN x This provides a mechanism for deposition. On the other hand, simple methyl groups in methyl-substituted perhydrogen cyclic silazanes require high temperatures for film formation, resulting in a very high carbon concentration in the resulting film. This is likely due to the lack of a low-energy exclusion mechanism for those methyl groups.

[0017] The preferred chemical structures and bonding configurations of N-alkyl-substituted perhydride cyclotrisilazanes have been designed to allow for the clean removal of alkyl groups at low to medium temperatures, resulting in pure Si-based thin films. Furthermore, the presence of H atoms relative to Si atoms minimizes steric hindrance, providing the precursor molecule with high accessibility to the surface site of the reactive substrate, regardless of whether the site is H-terminated (e.g., Si) or HO-terminated (e.g., SiO2). In other words, precursor adsorption to the substrate surface and possible partial decomposition by partial rupture of its ligand occur immediately upon contact with the substrate. This feature has important implications because, in contrast to what has been reported in the prior art, film nucleation and growth can occur instantaneously in the first cycle without the presence of a latency period, thus eliminating the need for substrate surface pretreatment, which adds additional complexity and ownership costs.

[0018] The film formation process according to this disclosure is by plasma activation, not by plasma enhancement or plasma assistance. In the plasma activation process, co-reactants (e.g., NH3, N2, N2+H2, hydrazine, oxygen, ozone, water, or H2) are introduced directly or remotely into a soft plasma, while the precursor exposure step is performed thermally without plasma involvement. Thus, the precursor adsorption step is activated by thermal and chemical energy from the substrate rather than from the plasma, thereby enabling the precursor (or partial precursor species resulting from the potential exclusion of some precursor ligands or attached radicals and groups depending on engagement with the substrate) to adsorb in a physically or chemically conformable manner onto various substrate surface topological shapes, such as via and trench structures with high aspect ratios. As a result, the subsequent remote or direct co-reactant plasma conformally forms the desired film with equal thickness across the entire substrate surface, even in highly aggressive device geometries.

[0019] The processing according to this disclosure is performed at a substrate temperature that results in pulsed application of the precursor to partial or complete decomposition of the precursor upon engagement with the substrate during each exposure cycle, in contrast to those limited to mere physical or chemical adsorption reactions of a complete precursor. Co-reactants are introduced later to complete the decomposition reaction and / or remove reaction by-products to ensure a clean film. Thus, since the precursor is already partially decomposed by the time it reaches the substrate surface, the processing requires only lower thermal, chemical, or plasma energy to grow the target film.

[0020] The degradation of the precursor in the method described herein is induced by the simultaneous action of three processes: partial removal of some ligands, adsorption of the precursor onto the substrate, thermal energy from the substrate, and activation of a soft plasma.

[0021] Suitable substrates include, without limitation, those composed of materials selected from the group consisting of silicon, silicon oxide, copper, platinum, titanium, titanium nitride, tantalum, and tantalum nitride.

[0022] The processes described here are not limited to silicon nitride (SiN x The process also applies equally to the reaction of N-alkyl-substituted perhydride cyclotrisilazanes with a nitrogen source, such as a direct or indirect soft plasma of NH3, N2, N2+H2, hydrazine, or methylamine, to form silicon oxide (SiO2), an oxygen source, such as a direct or indirect soft plasma of ozone, water, or O2, to form silicon oxide (SiO2), and a reactive hydrogen source, such as a direct or indirect soft plasma of H2, to form pure Si. x N y This method can be applied to the formation of compound thin films. The ratio of carbon (C / N) to nitrogen in the film is modulated by controlling the substrate temperature and the co-reactant pulse width.

[0023] Specifically, the control of the substrate temperature in the reaction region of the deposition chamber affects the chemical composition of the resulting silicon-containing thin film. Specifically, from the perspective of the chemical structure and bonding constitution of N-alkyl-substituted perhydridocyclotrisilazanes, the energetics of the reaction between the soft plasma and the source precursor at a higher but moderate substrate temperature (about 200 °C to about 650 °C, preferably about 200 °C to about 350 °C, etc.) results in the formation of a SiN film, while a low substrate temperature (room temperature to about 200 °C, preferably about 30 °C to about 200 °C) results in a SiC film composed of a simple Si-C and Si-N bond matrix without C-N bonds. x N y For the purposes of the present disclosure, the term "room temperature" can be understood to refer to a temperature of about 20 °C to about 27 °C. In both processes, but not limited thereto, the direct or remote soft plasma of a nitrogen-containing reactant such as NH3, N2, N2 + H2, hydrazine or methylamine is exposed to the adsorbed monolayer film on the substrate. The direct or remote soft plasma of a carbon-containing species such as acetylene can also be employed to form a silicon carbonitride thin film. The adsorbed N-alkyl-substituted perhydridocyclotrisilazane monolayer film reacts with the soft plasma and undergoes conversion to discrete atomic or molecular layers of a silicon carbonitride thin film via dissociation and / or decomposition enabled by or resulting from the substrate surface-induced treatment.

[0024] Since the formation of the film on the surface is not associated with the vapor-phase interaction of the precursor with the plasma, the process according to the present disclosure is clearly different from the plasma-enhanced chemical vapor deposition method (PE-CVD). During the purge step, that is, a mechanism for removing non-adsorbed (unreacted) precursors and co-reactants and by-products from the vapor phase by a vacuum or inert gas flow is not necessary, although such a step is suitable in some embodiments for eliminating the possibility of unwanted vapor-phase reactions. By-products of such reactions of the precursor with co-reactants and subsequent decomposition include, for example, ligands and partial ligands from the parent molecule and partially decomposed precursors. By-products can also include partially decomposed co-reactant species and objects formed from precursor ligands and co-reactant species.

[0025] In one embodiment, aspects of the present disclosure relate to the development and optimization of plasma activation treatment from one perhydridocyclotrisilazane, namely 1,3,5-tri(isopropyl)cyclotrisilazane (TICZ, C9H 27 N3Si3) containing three C atoms for each N in the form of a propyl group. The propyl group is eliminated at medium temperature in the form of the gaseous by-product propylene, as shown in Scheme 1.

[0026]

Chemical formula

[0027] Using such perhydridocyclotrisilazane, thin films of SiN x (0 < x < 1.33) can be produced at medium temperature. Thereby, the process uses an N-alkyl-substituted perhydridocyclotrisilazane precursor and a nitrogen-containing soft plasma co-reactant at medium temperature (substrate temperature of about 2 hundred degrees Celsius to about 650 degrees Celsius, preferably about 2 hundred degrees Celsius to about 350 degrees Celsius), and in a preferred embodiment, employs TICZ and a soft remote ammonia (NH3) plasma co-reactant to provide for forming a SiN x thin film. Since the range of substrate temperature encompasses all temperatures within that range, the temperature of about 2 hundred degrees Celsius to about 650 degrees Celsius can be understood to include temperatures such as about two hundred and twenty-five degrees Celsius, about two hundred and fifty degrees Celsius, about two hundred and seventy-five degrees Celsius, about three hundred degrees Celsius, about three hundred and twenty-five degrees Celsius, about three hundred degrees Celsius, about three hundred and twenty-five degrees Celsius, about three hundred and fifty degrees Celsius, about three hundred and seventy-five degrees Celsius, about four hundred degrees Celsius, about four hundred and twenty-five degrees Celsius, about four hundred and fifty degrees Celsius, about four hundred and seventy-five degrees Celsius, about five hundred degrees Celsius, about five hundred and twenty-five degrees Celsius, about five hundred and fifty degrees Celsius, about five hundred and seventy-five degrees Celsius, about six hundred degrees Celsius, about six hundred and twenty-five degrees Celsius, and about six hundred and fifty degrees Celsius, as well as all temperatures in between.

[0028] This exemplary process of depositing such a silicon nitride thin film on a substrate within the reaction region of a deposition chamber, in one cycle, includes heating the substrate to a temperature of about 200°C to about 650°C, preferably about 200°C to about 350°C; maintaining the substrate at about 200°C to about 650°C, preferably about 200°C to about 350°C; providing vapor-phase 1,3,5-tri(isopropyl)cyclotrisilazane into the reaction region containing the substrate together with a carrier gas and / or under vacuum; forming a monolayer film of 1,3,5-tri(isopropyl)cyclotrisilazane by adsorption onto the substrate surface; and exposing the adsorbed monolayer film on the substrate within the reaction region to a remote or direct soft plasma of a nitrogen-containing reactant. The adsorbed monolayer film of 1,3,5-tri(isopropyl)cyclotrisilazane reacts with the soft plasma and undergoes conversion to discrete atomic or molecular layers of a silicon nitride thin film through dissociation and / or decomposition enabled by or resulting from the substrate surface-induced treatment. The by-products of the conversion are removed from the reaction region through a purge step by an inert gas and / or vacuum. And this cycle is repeated a desired number of times to form a SiN x thin film of a desired thickness. The nitrogen-containing chemical species or co-reactants can be, for example, without limitation, NH3, N2, a mixture of N2 and H2, methylamine, and / or hydrazine, and currently NH3 is preferred.

[0029] In some embodiments, after forming a monolayer film of N-alkyl-substituted perhydridocyclotrisilazane by adsorption onto the substrate surface, unreacted N-alkyl-substituted perhydridocyclotrisilazane and its by-products are removed from the reaction region through a second purge step by an inert gas and / or vacuum.

[0030] The resulting SiN x (0 < x < 1.33) thin film's composition and optical properties were analyzed by in-situ real-time spectroscopic ellipsometry and X-ray photoelectron spectroscopy (XPS), and their wet etching rates were determined using standard IC industry etching solutions. The results are summarized below.

[0031] As a result, by adopting the process described here, high-quality silicon nitride (SiN) can be produced. x ) A thin film is formed on a substrate such as silicon oxide (SiO2) within an optimized substrate temperature window of approximately 200°C to 350°C, and the source precursor 1,3,5-tri(isopropyl)cyclotrisilazane (TICZ, C9H 27 As-deposited SiN can be grown by applying remote plasma pulses using N3Si3 and remote ammonia (NH3) soft plasma. Briefly, the process consists of four steps: a TICZ pulse without plasma, an optional N2 purge, an NH3 plasma pulse, and an N2 purge. As described below, the as-deposited SiN prepared by the process described herein is x The film was analyzed by spectroscopic ellipsometry and X-ray photoelectron spectroscopy (XPS). The wet etching rate (WER) was determined using a standard solution consisting of 0.5% hydrofluoric acid (HF) in deionized water. XPS analysis yielded a Si:N ratio of approximately 1:1 across the entire substrate temperature range, confirming the formation of the SiN phase. Real-time in-situ ellipsometry measurements showed SiN x They concluded that the growth exhibited non-self-limiting pulsation behavior. They also stated that for film growth at substrate temperatures above 200°C, the newly grown (as-grown) SiN x This resulted in an average refractive index of approximately 1.8.

[0032] SiN using the reaction of source precursor TICZ with NH3 plasma x Key findings from the development and optimization of cryogenic processing for films are as follows: TICZ is selected from those containing three carbon atoms per nitrogen in the form of propyl groups, which are readily eliminated at medium temperatures in the form of gaseous by-product propylene. TICZ is also produced in high yield and high purity from readily available starting materials as described below, thus demonstrating its suitability for mass production. This study is for high-quality Si 1.0 :N 1.0An optimized substrate temperature window ranging from 200 to 350°C was identified for film formation. Wet etching studies using a standard IC industry solution consisting of 0.5% HF in deionized H2O yielded viable etching rates that rivaled those reported in the literature. Ellipsometry analysis of film nucleation and growth characteristics confirmed that film formation is comparable to that of SiN in ALD and CVD. x In contrast to numerous previous reports in the literature on this topic, we demonstrated that it can occur instantaneously in the initial deposition cycle without the presence of a latency period, thus eliminating the need for substrate surface pretreatment, which would result in additional complexity and ownership costs. These results are for SiN using TICZ as the silicon source precursor. x This demonstrates that it is a viable option for incorporating newly emerging heterogeneous device structure manufacturing processes into the workflow.

[0033] In other embodiments, the disclosure uses an N-alkyl-substituted perhydride cyclotrisilazane precursor and a nitrogen-containing or carbon-containing soft plasma coreactant at low temperatures (substrate temperature from room temperature to about 200°C), and in preferred embodiments, a TICZ and a remote ammonia (NH3) soft plasma coreactant is used to form SiC x N y(Regarding the process of forming a (0.40 < x < 1.67 and 0.67 < y < 0.86) thin film. This exemplary process of depositing a silicon carbonitride thin film on a substrate within the reaction region of a deposition chamber includes, in one cycle, heating the substrate to a temperature from room temperature to about 200 °C, maintaining the substrate at a temperature from room temperature to about 200 °C, providing vapor-phase 1,3,5-tri(isopropyl)cyclotrisilazane into the reaction region containing the substrate together with a carrier gas and / or under vacuum, forming a monolayer film of 1,3,5-tri(isopropyl)cyclotrisilazane by adsorption onto the substrate surface, and exposing the adsorbed monolayer film on the substrate within the reaction region to a remote or direct soft plasma of a nitrogen-containing or carbon-containing reactant. The adsorbed monolayer film of 1,3,5-tri(isopropyl)cyclotrisilazane reacts with the soft plasma and undergoes conversion to discrete atomic or molecular layers of the silicon carbonitride thin film via dissociation and / or decomposition enabled by or resulting from the substrate surface-induced treatment. The by-products of the conversion are removed from the reaction region via a purge step with an inert gas and / or vacuum. And this cycle is repeated a desired number of times to form a SiC x N y thin film of the desired thickness.) The nitrogen-containing chemical species or co-reactants can be, for example, without limitation, NH3, N2, a mixture of N2 and H2, methylamine, and / or hydrazine, and currently NH3 is preferred. The carbon-containing chemical species or co-reactants can be, for example, acetylene.

[0034] Since the range of the substrate temperature encompasses all temperatures within that range, the temperature from room temperature to about 200 °C can be understood to include temperatures such as about 20 °C, about 25 °C, about 30 °C, about 45 °C, about 50 °C, about 60 °C, about 70 °C, about 80 °C, about 90 °C, about 100 °C, about 110 °C, about 120 °C, about 130 °C, about 140 °C, about 150 °C, about 160 °C, about 170 °C, about 180 °C, about 190 °C, and about 200 °C, and all temperatures in between.

[0035] In some embodiments, after forming a monolayer film of N-alkyl-substituted perhydridocyclotrisilazane by adsorption onto the substrate surface, unreacted N-alkyl-substituted perhydridocyclotrisilazane and its by-products are removed from the reaction region via a second purge step with an inert gas and / or vacuum.

[0036] Thereby, by employing the processes described herein, high-quality SiC x N y thin films can be grown from 1,3,5-tri(isopropyl)cyclotrisilazane and soft remote ammonia (NH3) plasma co-reactants. Briefly, the process involves four steps: thermal adsorption of TICZ onto the substrate at low temperature (TICZ pulses without plasma), an optional nitrogen (N2) purge, a soft NH3 remote plasma step, and an N2 purge. These steps are repeated until the desired film thickness is reached. The ratio of C to N in the film is modulated by controlling the substrate temperature in the range from room temperature to about 200 °C, preferably 30 °C to about 200 °C. In-situ analysis of the deposition process was performed using spectroscopic ellipsometry, and the film was analyzed by X-ray photoelectron spectroscopy (XPS). The findings of this study indicate that the combination of reduced substrate thermal budget and soft remote plasma provides an optimal low-energy environment for the controlled deposition of SiC x N y protective coatings.

[0037] As described below, low-temperature (near room temperature) SiC using TICZ and soft remote ammonia (NH3) plasma as co-reactants x N y deposition results in SiC x N y thin films in the substrate temperature range of 30 - 150 °C with 0.40 < x < 1.67 and 0.67 < y < 0.86. XPS analysis shows SiC x N yThe film was shown to consist mostly of a temperature-independent matrix of simple cross-linked Si-C and Si-N bonds. Real-time in-situ angle-resolved ellipsometry showed that all films grew in a plasma pulse regime with instantaneous nucleation and growth without the latency period reported in the literature for ALD and P-CVD operations. This feature indicates that this SiC x N y The process becomes promising from a manufacturing standpoint due to the elimination of pre-deposited substrate surface treatment, either ex-situ or in-situ, resulting in increased processing efficiency and reduced processing steps and ownership costs. Therefore, these findings suggest that applying soft, remote plasma in conjunction with a reduction in the substrate thermal budget, directed so that the TICZ and NH3 coreactants react only on the substrate surface, is promising for SiC in low-energy environments for potential applications requiring thermally fragile and chemically susceptible substrates, including plastics and polymers. x N y This constitutes a promising approach for the growth of protective coatings.

[0038] Further embodiments relate to a method for depositing a silicon oxide thin film onto a substrate within the reaction region of a deposition chamber. The method comprises the steps of: heating a substrate to a temperature of about 200°C to about 650°C, preferably about 200°C to about 350°C in one cycle; maintaining the substrate at about 200°C to about 650°C, preferably about 200°C to about 350°C; providing a precursor containing an N-alkyl-substituted perhydride cyclotrisilazane in vapor phase to a reaction region including the substrate together with a carrier gas and / or under vacuum; forming a monolayer film of the N-alkyl-substituted perhydride cyclotrisilazane by adsorption onto the substrate surface; and exposing the adsorbed monolayer film on the substrate in the reaction region to a soft plasma containing oxygen-containing reactants, wherein the adsorbed monolayer film of the N-alkyl-substituted perhydride cyclotrisilazane reacts with the soft plasma and undergoes conversion to discrete atoms or molecular layers of the silicon oxide thin film via dissociation and / or decomposition caused by or enabled by the substrate surface-induced treatment, and the by-products of the conversion are removed from the reaction region by an inert gas and / or under vacuum via a purging step. This cycle is then repeated a desired number of times to form a silicon oxide thin film of a desired or predetermined thickness. The oxygen-containing chemical species or co-reactants may be, for example, ozone, O2, and water, without limitation. A preferred N-alkyl-substituted perhydride cyclotrisilazane is TICZ.

[0039] Since the substrate temperature range encompasses all temperatures within that range, the temperature range of approximately 200°C to approximately 650°C can be understood to include temperatures such as approximately 225°C, approximately 250°C, approximately 275°C, approximately 300°C, approximately 325°C, approximately 300°C, approximately 325°C, approximately 350°C, approximately 375°C, approximately 400°C, approximately 425°C, approximately 450°C, approximately 475°C, approximately 500°C, approximately 525°C, approximately 550°C, approximately 575°C, approximately 600°C, approximately 625°C, and approximately 650°C, as well as all temperatures in between.

[0040] In some embodiments, a monolayer film of N-alkyl-substituted perhydridecyclotrisilazane is formed by adsorption onto the substrate surface, after which unreacted N-alkyl-substituted perhydridecyclotrisilazane and its by-products are removed from the reaction region via a second purging step using an inert gas and / or vacuum.

[0041] In a further embodiment, the Disclosure provides a method for depositing a silicon thin film onto a substrate in a reaction region of a deposition chamber, the method comprising the steps of: heating the substrate to a temperature of about 200°C to about 650°C, preferably about 200°C to about 350°C in one cycle; maintaining the substrate at about 200°C to about 650°C, preferably about 200°C to about 350°C; providing a precursor comprising an N-alkyl-substituted perhydride cyclotrisilazane in the vapor phase together with a carrier gas and / or under vacuum to the reaction region including the substrate; and adsorption of N-alkyl onto the substrate surface. The process comprises the steps of forming a monolayer film of a substituted perhydride cyclotrisilazane and exposing the adsorbed monolayer film on a substrate within a reaction region to a soft plasma of hydrogen-containing reactants, wherein the adsorbed N-alkyl-substituted perhydride cyclotrisilazane monolayer film reacts with the soft plasma and undergoes conversion to discrete atoms or molecular layers of the silicon thin film via dissociation and / or decomposition caused by or enabled by the substrate surface treatment, and the byproducts of the conversion are removed from the reaction region by an inert gas and / or vacuum via a purging step. This cycle is then repeated a desired number of times to form a silicon thin film of a desired or predetermined thickness. The hydrogen-containing chemical species or co-reactants may be, for example, H2, without limitation. A preferred N-alkyl-substituted perhydride cyclotrisilazane is TICZ.

[0042] Since the substrate temperature range encompasses all temperatures within that range, the temperature range of approximately 200°C to approximately 650°C can be understood to include temperatures such as approximately 225°C, approximately 250°C, approximately 275°C, approximately 300°C, approximately 325°C, approximately 300°C, approximately 325°C, approximately 350°C, approximately 375°C, approximately 400°C, approximately 425°C, approximately 450°C, approximately 475°C, approximately 500°C, approximately 525°C, approximately 550°C, approximately 575°C, approximately 600°C, approximately 625°C, and approximately 650°C, as well as all temperatures in between.

[0043] In some embodiments, a monolayer film of N-alkyl-substituted perhydridecyclotrisilazane is formed by adsorption onto the substrate surface, after which unreacted N-alkyl-substituted perhydridecyclotrisilazane and its by-products are removed from the reaction region via a second purging step using an inert gas and / or vacuum.

[0044] The present invention will now be described in conjunction with the following non-limiting embodiments.

[0045] Example 1: Formation of a SiN thin film Precursor synthesis Under an argon atmosphere, a 5-liter four-necked flask equipped with a condenser, overhead stirrer, pot thermometer, subsurface immersion tube, and dry ice condenser was loaded with 909 grams of methyl t-butyl ether. The mixture was cooled to -40°C, and then 303.0 grams (3 moles) of dichlorosilane were gradually added to the pot. Then, 364.7 grams (6.0 moles) of isopropylamine were added via the immersion tube over a period of 2.5 hours at a temperature in the range of -30 to -20°C. After the addition was complete, the reaction mixture was gradually heated to 25°C and stirred at this temperature for 8 to 14 hours. This step was followed by the addition of 177.4 g (3 moles) of isopropylamine at a temperature in the range of 0 to 40°C, and then a subsequent addition of 227.3 grams of methyl t-butyl ether. The mixture was stirred for 6 to 16 hours and monitored by gas chromatography (GC). The reaction solution was then filtered, and the solvent was removed from the filtrate under reduced pressure at a temperature below 50°C. Repeated filtration and fractional distillation of the clear filtrate yielded 64.5 g (24.66 mol) of TICZ.

[0046] The TICZ vapor pressure was determined by a combination of distillation temperature, pressure reading (<10 torr), and pressure-cell DSC measurement (>10 torr). These measurements were taken using a TA Instruments Pressure DSC25P measuring instrument with Tzero Hermetic Pinhole (75 μm) Lids, sample sizes of 2–5 mg, and a gradient of 15°C / min. Figure 1 shows the actual vapor pressure data from distillation and DSC measurements, as well as the fit of the Antoine equation [Log(P)=AB / (C+T)] over the range of 0.14–760 torr.

[0047] Processing conditions for SiN thin film deposition A Picosun R-200 R&D system, equipped with a sample load lock and remotely inductively coupled plasma (ICP) power supply to maintain the cleanliness and vacuum integrity of the reaction chamber, was used for processing development and optimization. All deposition was performed on substrates consisting of 1000 nm thick silicon dioxide thermally grown on n-doped Si wafers obtained from Addison Engineering. Upon receipt, samples were loaded, and before each deposition test, in-situ NH3 plasma cleansing was performed for 5 minutes at a plasma frequency of 13.56 MHz and plasma power of 2000 W.

[0048] The TICZ precursor was loaded into a special bubble generator connected to the Picosun precursor manifold system and heated to 50°C. All transport lines were also heated to 90°C to suppress premature precursor aggregation before entering the reaction chamber. N2 gas was used as the carrier gas and set to 100 sccm.

[0049] SiN is produced by the reaction of TICZ and NH3 plasma. xThe processing development and optimization for this were carried out in two stages. In the first "proof of concept" stage, a systematic set of screening experiments were performed to identify the optimal values ​​for the TICZ pulse, purge step, and NH3 plasma pulse duration, as well as the N2 purge gas flow rate, NH3 remote plasma flow rate, and plasma power. In the second "processing optimization" stage, key experimental parameters were set as shown in Figure 2, and the substrate temperature was varied from 50°C to 350°C in 50°C increments. Precursor exposure time, plasma pulse width, and purge time were identified for substrate temperatures of 50, 150, 200, 250, 300, and 350°C, except that the precursor purge time was not applied in the 350°C test. The NH3 remote plasma frequency, flow rate, and power were set to 13.56 MHz, 40 sccm, and 2000 W, respectively. The samples were then transferred to a load lock system and cooled to room temperature in an N2 atmosphere before removal from the Picosun system.

[0050] Regarding XPS analysis, SiN x The sample is covered with zinc oxide (ZnO) approximately 10-15 nm thick. x The ZnO of ALD was capped with a layer to prevent surface contamination during transport and handling. x The process involved a 100-cycle reaction using diethylzinc (DEZ) as the Zn source and water as the oxygen source. x Except for the case of a 50°C sample, SiN x The material was grown in situ immediately after deposition and at the same temperature, and the temperature was changed to ZnO x The temperature was raised to 150°C for deposition. The process consisted of four steps: a 0.1-second DEZ pulse, a 5-second N2 purge, a 0.1-second water vapor pulse, and a 5-second N2 purge.

[0051] analytical techniques Real-time, in-situ angle-resolved ellipsometry was performed using a Woollam iSE ellipsometer at wavelengths ranging from 400 to 1000 nm. The ellipsometer system was directly mounted on a P-CVD (pulsed CVD) reaction chamber with the incident light beam directed onto the substrate through a quartz glass window at an incident angle of 60.8°, and the reflected light beam captured by the detector. The resulting data was analyzed using CompleteEASE software. The substrate was modeled as a thermal SiO2 layer approximately 1000 nm thick on Si. The thickness of the SiO2 layer was measured in situ before each P-CVD test.

[0052] XPS was performed on a PHI Quantum 2000 system at Eurofins EAG Materials Science, LLC. X-rays were generated at 1486.6 eV from a monochromatic Alkα source and directed at the sample at an input angle of ±23° and an extraction angle of 45°. Detailed compositional analysis was performed using Ar + XPS was performed using an ion gun at 2 keV, with a 4 mm × 2 mm raster and a sputtering rate of 3.8 nm / min. Since the Si, N, C, and O peaks were sufficiently separated from each other, deconvolution was not applied to the data. All data processing (aggregation) was performed using CasaXPS software from Casa Software Ltd. Montage plots were generated using MultiPak software produced by Ulvac-phi, Inc. Depth profile plots were generated using Microcal Origin manufactured by Microcal Software, Inc. The assignment of high-resolution XPS peaks was performed according to the calibration procedure described in ISO 15472:2010 "Surface chemical analysis - X-ray photoelectron spectrometer - Energy scale calibration".

[0053] Wet etching was investigated at room temperature using a standard IC industry solution consisting of 0.5% hydrofluoric acid (HF) in deionized water.

[0054] Precursor analysis 1,3,5-Tri(isopropyl)cyclotrisilazane (TICZ, C9H 27 One additional advantageous effect of N3Si3) is that, as mentioned above, it can be produced in high yield and purity from readily available starting materials. This ensures its suitability for mass production. The relevant properties of TICZ are shown in Table I, and its vapor pressure versus temperature parameters are shown in Figure 1. It should be noted that the precursor synthesis recipe described above can also produce other analogs such as 1,3,5-tri(ethyl)cyclotrisilazane and 1,3,5-tri(t-butyl)cyclotrisilazane, which have different volatility and deposition characteristics.

[0055] [Table 1]

[0056] Ellipsometry analysis Figure 3 shows in-situ real-time ellipsometry profiles of film thickness versus deposition duration for films grown at a substrate temperature of 200°C for TICZ pulse times of 0.4 seconds, 1.0 seconds, 2.0 seconds, 3.0 seconds, and 5.0 seconds. As shown in the profiles, the film thickness continues to increase with the precursor pulse time and does not saturate regardless of the precursor pulse time. This behavior indicates that the TICZ adsorption step is not self-limiting, and SiN x This supports the conclusion that film growth does not occur via ALD processing. The same film thickness dependence with respect to pulse time was observed across the entire substrate temperature range verified from 50°C to 350°C. This indicates that film formation does not occur via the ALD growth mode within the entire verified processing window.

[0057] Similarly, Figures 4 and 5 show plots of real-time ellipsometry measurements in-situ of film thickness versus deposition time for substrate temperatures of 150, 175, 200, 225, 300, and 350°C. Figure 4 shows, as expected, that film thickness increases with longer deposition times. However, a gradual decrease in the slope of each film thickness curve was also observed at higher substrate temperatures. This decrease indicates a decrease in the growth rate per cycle (GPC) due to the increase in substrate temperature. The decrease in GPC is suggested to be due to a reduction in the vapor partial pressure of the precursor in the reaction region near the substrate. This decrease is thought to be likely due to the geometry of the deposition chamber, which, with increasing substrate temperature, induces additional heating at the point where the precursor is introduced into the reactor, resulting in some precursor decomposition before reaching the reaction region. Alternatively, the decrease may be caused by a higher frequency of recombination of precursor species and associated ligands due to an increase in the thermal budget and their subsequent decomposition from the substrate surface, consequently limiting the TICZ and NH3 reaction rates.

[0058] Furthermore, Figure 5 shows SiN produced from ALD and CVD. x In contrast to numerous previous reports in the literature on this topic, film formation occurs instantaneously in the initial deposition cycle without any latency period or increased delay in film nucleation and growth. This feature eliminates the need for substrate surface pretreatment, thus improving the manufacturing process flow of SiN for heterogeneous device structures. x This is important because it eliminates the added complexity and cost associated with incorporating the deposit. Furthermore, Table II shows the ellipsometry derivation for film thickness, growth rate per cycle (GPC), and newly deposited SiN x The refractive index of the film is shown as a function of the substrate temperature.

[0059] [Table 2]

[0060] XPS analysis The selected film thickness was also confirmed by XPS depth profile analysis. SiN xThe Zn, Si, N, C, and O concentrations versus penetration depth in the film were compared for newly deposited SiN grown at substrate temperatures of 200°C and 300°C. x The membranes were evaluated by XPS depth profile analysis, as shown in Figures 6 and 7, respectively.

[0061] Measurements revealed a decrease in C concentration of approximately 42 atomic% and 15 atomic% for films grown at substrate temperatures of 50°C and 150°C, respectively. As shown in Figure 6, the values ​​fell below the detection limit of XPS at substrate temperatures above 200°C. Therefore, the XPS results indicate that the minimum thermal budget required for the efficient reaction of TICZ and NH3 is obtained at 200°C, resulting in complete precursor dissociation and removal of reaction byproducts from the deposited region. Similarly, O concentrations of approximately 11 atomic% and 6 atomic% were recorded for films grown at substrate temperatures of 50°C and 150°C, respectively. This value decreased to approximately 5 atomic% at substrate temperatures above 200°C, as shown in Figure 6. Oxygen contamination was observed in in-situ P-CVD zinc oxide (ZnO) x This is due to O diffusion during the cap layer deposition step.

[0062] Table III shows representative SiN values ​​in bulk films grown at 200°C, 250°C, and 300°C at a depth of approximately 25 nm. x The atomic concentrations are given. The data in Table III and Figures 6 and 7 demonstrate that the samples deposited at temperatures above 200°C have a Si:N ratio of approximately 1:1.

[0063] High-resolution XPS spectra of Si2p, N1s, C1s, and O1s bond energy pairs and penetration depths were obtained for SiN deposited at 200°C and 300°C. x The films are shown in Figures 8 and 9, respectively. The data demonstrate both sets of films consisting of a SiN phase with low concentrations of O and virtually no C contamination. The N1s spectrum shows the Si-N bond, the main peak due to N(-Si)3 from the nitride, and silicon oxynitride (Si x N y O z It should be noted that this includes a small peak attributable to ON(-Si)2 related to ).

[0064] [Table 3]

[0065] Wet etching speed Wet etching was investigated using a standard IC industry solution consisting of 0.5% hydrofluoric acid (HF) in deionized water. The results are summarized in Table II. The wet etching rates observed for films deposited at 300°C are comparable to those reported in prior art for, for example, LPCVD films grown at 770°C and PE-ALD films deposited at 250°C etched with a mild etching solution consisting of 1:300 HF:H2O, as well as PE-ALD films grown at 270-350°C and treated with a more diluted wet etching solution consisting of 1:500 HF:H2O.

[0066] Example 2: SiC x N y Formation of thin films Experimental sedimentation conditions All experiments were conducted in the same Picosun R-200 R&D reactor as described above. SiC x N y The film growth experiment was conducted in two stages. In the first screening stage, systematic scope experiments were performed to establish optimized test parameters including the processing operating pressure, remote NH3 plasma power, and precursor, NH3 and N2 flow rates, as well as the length of the pre-deposition plasma processing step and the duration of the TICZ, N2 purge, and remote NH3 plasma pulse steps. Once this stage was completed and an appropriate set of experimental parameters was identified, the second processing optimization stage was carried out to develop SiC x N yThe compositional, physical, and chemical properties were determined as a function of substrate temperature in the range of 30°C to 200°C. For this stage, the NH3 flow rate was kept constant at 40 sccm, while the remote plasma power and frequency were set to 2000 W and 13.56 MHz, respectively. Table IV summarizes the important test parameters.

[0067] Table IV. Soft Remote Plasma SiC x N y Important processing parameters for sedimentation [Table 4]

[0068] SiC x N y Following the growth test, in situ, zinc oxide (ZnO) with a thickness of approximately 10-15 nm was grown. x )By depositing a cap layer, SiC is protected from exposure to air and during subsequent transport and handling. x N y Contamination was prevented. ZnO x For the steps, a standard ALD process was adopted. SiC at 50°C x N y Except for films, the temperature is ZnO x SiC to be heated to 150°C for the growth step x N y The substrate temperature was maintained at the same value as the deposition step. ALD ZnO x The treatment employed diethylzinc (DEZ) and water (H2O) as the Zn and O sources, respectively. Separation was performed by 5 seconds of N2 purging, accompanied by 0.1 seconds of DEZ pulses and 0.1 seconds of H2O vapor pulses.

[0069] At the conclusion of each deposition test, the samples were transferred back to the load lock system and kept under an N2 atmosphere until they cooled to room temperature before removal from the Picosun system.

[0070] analytical techniques SiC x N yTo investigate the composition and chemical bonding characteristics of the film, the same analytical techniques as described above were employed.

[0071] XPS analysis Table V shows the atomic concentration percentages of Si, C, N, and O in the films deposited at 50, x x N y 150, and 200 °C. The values were determined by quantitative XPS analysis as shown in Figures 10 and 11 for the SiC

[0072] [[ID=??]]

Table 5

[0073] The oxygen content of the film was approximately 10 at% at 50 °C and decreased to 3 - 5 at% at higher temperatures. The presence of this low concentration of O may be due to the reaction of H2O with SiC x during the ZnO cap layer step. It may also result from impurities in NH3 or N2, and / or well-known issues with plasma etching of the Al2O3 dielectric liner used in the ICP plasma source. As seen in Table V and Figures 10 and 11, a gradual decrease in the C concentration was also observed at higher substrate temperatures, while the N content showed a constant increase. x N y These trends are consistent with the observation that the combination of reduced substrate thermal budget and soft remote plasma provides an optimal low-energy environment for alkyl groups to undergo a slow and controlled dissociation reaction by the parent molecule. With the increase in substrate temperature, a higher degree of bond dissociation and the thermal activation energy for the redistribution of Si, C, and N bonds within the SiC

[0074] N x N y film increase.

[0075] Si2p, N1s, C1s, and O1s binding energies for SiC x N y It seems there is an unclear "??" in the original text where it says "

Table 5

[0076] High-resolution XPS analysis shows that the SiC x N y film appears to be mostly a matrix of simple cross-linked Si-C and Si-N bonds for substrate temperatures below 150 °C. With the Si2p and N1s peaks corresponding to the SiN phase, no C was observed in the film within the XPS detection limit at 200 °C.

[0077] This result is fundamentally different from the aforementioned film. In the aforementioned film, for the SiC x N (00end]] y the C1s peak in undergoes a transition from a C-C type bond to a C-Si type bond and then to a C-N type bond in response to an increase in the substrate temperature, while the N1s peak shows a transition from an N-C bond with some contribution from the N-C type bond to mostly an N-Si bond. At the same time, it has been reported that Si2p develops mainly from Si-N, Si-O, and Si-C type bonds to Si-Si bonds, along with Si-N and Si-C bonds. These results were due to the existence of various temperature-dependent complex bond configurations in the aforementioned SiC x N y film. Different from the previously reported film, the SiC of the invention has no change in the bond configuration or chemical structure with temperature x N ySimple Si-C and Si-N bonds in films provide stable and unchanging SiC in applications requiring thermally brittle and chemically susceptible substrates, including plastics and polymers. x N y Provides a matrix.

[0078] The results described and demonstrated here differ from conventional findings in the literature, for example, in atmospheric pressure plasma CVD (AP-PECVD) using triethylsilane (HSiEt3, TES) and N2 as Si, C, and N sources. Conventional findings have reported that the C1s peak shows development from CC-type bonding through C-Si-type bonding to CN-type bonding, while the N1s peak shows a transition from NC-type bonding, with some contribution from NC-type bonding, to N-Si bonding for the majority. At the same time, it has been reported that Si2p, along with Si-N and Si-C bonds, develops mainly from Si-N, Si-O, and Si-C-type bonding to Si-Si bonding. These results were attributed to the presence of various temperature-dependent complex bond configurations in SiCN films, as described in numerous other reports by various researchers.

[0079] Therefore, XPS analysis, when applied in a pulsed mode directed to reduce the substrate thermal budget, allows for the reduction of the substrate thermal budget, and is suitable for (i) SiC with a simple crosslinked Si-C and SiC with a temperature-independent bond configuration of Si-N bonds. x N y (ii) a matrix, and a gradual and controlled decrease in C content with respect to increasing substrate temperature.

[0080] Ellipsometry analysis In-situ real-time ellipsometry studies were conducted to determine the properties and characteristics of the pulsed deposition process, including the adsorption and reaction pathways of the TICZ source precursor and NH3 remote plasma, and the resulting SiC x N yWe performed membrane nucleation and growth profiles. For this purpose, Figure 14 shows the SiC nucleation and growth profiles as a function of deposition time for TICZ pulse times of 0.1, 0.2, 0.4, and 0.8 seconds. x N y The film thickness is displayed. The substrate temperature was maintained at 150°C in all tests. The data shows a constant increase in higher TICZ pulse widths, indicating that it does not reach a plateau where the increase stops, as was expected in the ALD process. This trend was observed across the entire substrate temperature window being verified, and SiC x N y This indicates that pulsed deposition occurs in P-CVD rather than the ALD regime. One advantageous effect of the plasma pulsed mode is the potential partial decomposition of the parent TICZ precursor in response to adsorption to the substrate surface, and its conductivity for film deposition in a lower thermal budget window before reaction with NH3.

[0081] Similarly, Figure 15 gives in-situ, real-time, angle-resolved ellipsometry measurements of film thickness versus deposition time for substrate temperatures of 30, 60, 90, 120, 150, and 170°C. The plots show that nucleation and growth occur instantaneously, as indicated by the immediate increase in film thickness within the first deposition cycle. This feature has been reported in the literature for other ALD and P-CVD operations, particularly for SiC. x N y This is important because it demonstrates the absence of a latency period before the start of film formation. Due to the absence of such a latency period, plasma pulsed SiC x N y This becomes more promising from a manufacturing standpoint. This is because it eliminates the need for pre-deposited substrate surface treatment in ex-situ or in-situ, thus reducing SiC x N y This is because it reduces the number of processing steps required to grow thin films.

[0082] Furthermore, Figure 15 shows the gradual decrease in the slope of the film thickness curve with increasing substrate temperature and the resulting SiC per cycle. x Ny The growth rate is shown. The decrease in GPC at higher substrate temperatures may be potentially caused by (i) a decrease in TICZ vapor partial pressure near the substrate due to the reactor geometry, including a gradual increase in precursor decomposition at the point of introduction into the chamber and at that point before reaching the substrate, and / or (ii) a higher rate of deposition of precursor and associated sites from the substrate surface prior to the NH3 coreactate step due to an increase in the thermal budget. Finally, ex-situ ellipsometry measurements yielded refractive indices of approximately 1.49, 1.51, and 1.80 for films deposited at 50, 150, and 200°C, respectively.

[0083] Wet etching speed Wet etching rate (WER) studies yielded values ​​of 2310, 732, and 99 nm / min for films grown at 50, 150, and 200°C, respectively.

[0084] Those skilled in the art will see that modifications can be made to the above embodiments without departing from the broad concept of the present invention. Therefore, it will be understood that the present invention is not limited to the specific embodiments disclosed, but encompasses modifications within the spirit and scope of the invention as defined by the appended claims.

Claims

1. A method for depositing a silicon nitride thin film on a substrate within the reaction region of a deposition chamber, wherein in one cycle, A step of selecting a precursor comprising an N-alkyl-substituted perhydride cyclotrisilazane containing at least two carbon atoms for each nitrogen atom, The steps include heating the substrate to a temperature of approximately 200°C to approximately 650°C, The steps include maintaining the substrate at a temperature of approximately 200°C to approximately 650°C, A step comprising providing the precursor in vapor phase together with a carrier gas and / or under vacuum to the reaction region including the substrate, wherein the precursor is physically adsorbed and partially decomposed, and the partial decomposition removes at least one ligand from the precursor upon contact with the substrate without resulting in complete dissociation of the precursor, The steps include forming a monolayer film of the partially decomposed N-alkyl-substituted perhydride cyclotrisilazane by physical adsorption onto the surface of the substrate, The process includes the formation of the partially decomposed monolayer film and, after the partial decomposition, performing one plasma activation treatment for each deposition cycle by exposing the adsorbed monolayer film on the substrate within the reaction region to a low-energy soft plasma consisting of one hydrogen-containing reactant and one nitrogen-containing reactant, either remotely or directly, using a set of processing parameters. The adsorbed and partially decomposed monolayer film of N-alkyl-substituted perhydridecyclotrisilazane reacts with the soft plasma provided in the plasma activation treatment and undergoes conversion to a molecular layer of silicon nitride thin film through dissociation and / or decomposition caused by or enabled by a substrate surface-induced treatment selected from the group consisting of energy transfer, remote plasma application, direct plasma application, oxidation and / or reduction. The growth of the molecular layer of the silicon nitride thin film occurs during the one cycle without the presence of a latency period. A method wherein the by-products of the conversion are removed from the reaction region via a purging step using an inert gas and / or the vacuum.

2. The method according to claim 1, further comprising the step of removing unreacted N-alkyl-substituted perhydride cyclotrisilazane and its by-products from the reaction region via a second purging step using an inert gas and / or vacuum, after the step of forming the monolayer film of the N-alkyl-substituted perhydride cyclotrisilazane by adsorption onto the surface of the substrate.

3. The method according to claim 1, wherein the temperature of the substrate is approximately 200°C to approximately 350°C.

4. The method according to claim 1, wherein the N-alkyl-substituted perhydride cyclotrisilazane is 1,3,5-tri(isopropyl)cyclotrisilazane.

5. The nitrogen-containing reactant is NH ３ , N ２ The method according to claim 1, comprising methylamine and / or hydrazine.

6. The method according to claim 1, wherein the cycle is repeated until a thin film of a predetermined thickness is achieved.

7. A method for depositing a silicon oxide thin film on a substrate within the reaction region of a deposition chamber, wherein in one cycle, A step of selecting a precursor comprising an N-alkyl-substituted perhydride cyclotrisilazane containing at least two carbon atoms for each nitrogen atom, The steps include heating the substrate to a temperature of approximately 200°C to approximately 650°C, The steps include maintaining the substrate at approximately 200°C to approximately 650°C, A step comprising providing the precursor in vapor phase together with a carrier gas and / or under vacuum to the reaction region including the substrate, wherein the precursor is physically adsorbed and partially decomposed, and the partial decomposition removes at least one ligand from the precursor upon contact with the substrate without resulting in complete dissociation of the precursor, The steps include forming a monolayer film of the partially decomposed N-alkyl-substituted perhydridecyclotrisilazane by physical adsorption onto the surface of the substrate, The steps include: forming the partially decomposed monolayer film and, after the partial decomposition, performing one plasma activation treatment for each deposition cycle by remotely or directly exposing the adsorbed monolayer film on the substrate within the reaction region to a low-energy soft plasma consisting of oxygen-containing reactants using a set of processing parameters; Equipped with, The adsorbed, partially decomposed N-alkyl-substituted perhydride cyclotrisilazane monolayer reacts with the soft plasma provided in the 1 plasma activation treatment and undergoes conversion to a silicon oxide thin film molecular layer via dissociation and / or decomposition caused by or enabled by a substrate surface-induced treatment selected from the group consisting of energy transfer, remote plasma application, direct plasma application, oxidation and / or reduction. The by-products of the conversion are removed from the reaction region by an inert gas and / or by vacuum via a purging step. A method wherein the growth of the molecular layer of the silicon oxide thin film occurs during one cycle without the presence of a latency period.

8. The method according to claim 7, further comprising the step of removing unreacted N-alkyl-substituted perhydride cyclotrisilazane and its by-products from the reaction region via a second purging step using an inert gas and / or vacuum, after the step of forming the monolayer film of the N-alkyl-substituted perhydride cyclotrisilazane by adsorption onto the surface of the substrate.

9. The method according to claim 7, wherein the temperature of the substrate is approximately 200°C to approximately 350°C.

10. The method according to claim 7, wherein the N-alkyl-substituted perhydride cyclotrisilazane is 1,3,5-tri(isopropyl)cyclotrisilazane.

11. The oxygen-containing reactant is ozone, water and / or O ２ The method according to claim 7, wherein the plasma is present.

12. The method according to claim 7, wherein the cycle is repeated until a thin film of a predetermined thickness is achieved.

13. A method for depositing a silicon carbonitride thin film on a substrate within the reaction region of a deposition chamber, wherein in one cycle, A step of selecting a precursor comprising an N-alkyl-substituted perhydride cyclotrisilazane containing at least two carbon atoms for each nitrogen atom, The steps include heating the substrate to a temperature of room temperature to approximately 200°C, The steps include maintaining the substrate at room temperature to approximately 200°C, The steps include providing the vapor phase precursor together with a carrier gas and / or under vacuum to the reaction region including the substrate, The steps include forming a monolayer film of the N-alkyl-substituted perhydride cyclotrisilazane by adsorption onto the surface of the substrate, The steps include: exposing the adsorbed monolayer film on the substrate within the reaction region to a soft plasma containing nitrogen-containing reactants, Equipped with, The adsorbed monolayer film of N-alkyl-substituted perhydridecyclotrisilazane reacts with the soft plasma and undergoes conversion to a molecular layer of silicon carbonitride thin film via dissociation and / or decomposition caused by or enabled by the substrate surface-induced treatment. A method wherein the by-products of the conversion are removed from the reaction region by an inert gas and / or by vacuum via a purging step.

14. The method according to claim 13, further comprising the step of removing unreacted N-alkyl-substituted perhydride cyclotrisilazane and its by-products from the reaction region via a second purging step using an inert gas and / or vacuum, after the step of forming the monolayer film of the N-alkyl-substituted perhydride cyclotrisilazane by adsorption onto the surface of the substrate.

15. The method according to claim 13, wherein the N-alkyl-substituted perhydride cyclotrisilazane is 1,3,5-tri(isopropyl)cyclotrisilazane.

16. The nitrogen-containing reactant is NH ３ , N ２ The method according to claim 13, comprising methylamine and / or hydrazine.

17. The method according to claim 13, wherein the cycle is repeated until a thin film of a predetermined thickness is achieved.

18. The method according to claim 13, wherein the substrate surface induction treatment is energy transfer, remote plasma application, direct plasma application, oxidation and / or reduction.

19. A method for depositing a silicon thin film on a substrate within the reaction region of a deposition chamber, wherein in one cycle, A step of selecting a precursor comprising an N-alkyl-substituted perhydride cyclotrisilazane containing at least two carbon atoms for each nitrogen atom, The steps include heating the substrate to a temperature of approximately 200°C to approximately 650°C, The steps include maintaining the substrate at approximately 200°C to approximately 650°C, A step comprising providing the precursor in vapor phase together with a carrier gas and / or under vacuum to the reaction region including the substrate, wherein the precursor is physically adsorbed and partially decomposed, and the partial decomposition removes at least one ligand from the precursor upon contact with the substrate without resulting in complete dissociation of the precursor, The steps include forming a monolayer film of the partially decomposed N-alkyl-substituted perhydride cyclotrisilazane by physical adsorption onto the surface of the substrate, The process includes the formation of the partially decomposed monolayer film and, after the partial decomposition, performing one plasma activation treatment for each deposition cycle by remotely or directly exposing the adsorbed monolayer film on the substrate within the reaction region to a low-energy soft plasma consisting of hydrogen-containing reactants using a set of processing parameters, The adsorbed, partially decomposed N-alkyl-substituted perhydride cyclotrisilazane monolayer reacts with the soft plasma provided in the 1 plasma activation treatment and undergoes conversion to a silicon thin film molecular layer via dissociation and / or decomposition caused by or enabled by a substrate surface-induced treatment selected from the group consisting of energy transfer, remote plasma application, direct plasma application, oxidation and / or reduction. The by-products of the conversion are removed from the reaction region by an inert gas and / or by vacuum via a purging step. A method wherein the growth of the molecular layer of the silicon thin film occurs during one cycle without the presence of a latency period.

20. The method according to claim 19, further comprising the step of removing unreacted N-alkyl-substituted perhydride cyclotrisilazane and its by-products from the reaction region via a second purging step using an inert gas and / or vacuum, after the step of forming the monolayer film of the N-alkyl-substituted perhydride cyclotrisilazane by adsorption onto the surface of the substrate.

21. The method according to claim 19, wherein the temperature of the substrate is approximately 200°C to approximately 350°C.

22. The method according to claim 19, wherein the N-alkyl-substituted perhydride cyclotrisilazane is 1,3,5-tri(isopropyl)cyclotrisilazane.

23. The method according to claim 19, wherein the cycle is repeated until a thin film of a predetermined thickness is achieved.

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