The semiconductor industry is being radically impacted by the placing of greater emphasis on the ... more The semiconductor industry is being radically impacted by the placing of greater emphasis on the development of hetero-devices and systems that will act as essential drivers for a wide spectrum of technological applications. The introduction of new materials and their integration with currently used materials are projected to replace integrated circuitry (IC) design and device scaling as the key enablers to the realization of improved device performance and larger density gains. Yet material selection has been constrained by existing fabrication process technology. To date, fabrication processes have dictated material selection by limiting chemical sources or precursors to those that match existing process tools associated with chemically based vapor phase processes and their variants, which in turn limits material compositions in ICs. The processing and integration of new materials compositions and structures will require the introduction of new deposition and etching processes, and manufacturing worthy tool designs and associated protocols that provide new methods for atomic-level control. To this end, a novel manufacturing paradigm is presented comprising a method and system for real-time, closed-loop monitoring and control of synthesis, supply, and consumption of precursors in process intensification techniques including chemical vapor deposition (CVD), atomic layer deposition (ALD), atomic layer etching (ALE), and other IC manufacturing processes. This intelligent automated manufacturing approach is consistent with a central component of the semiconductor industry’s recent adoption of Industry 4.0., including vertical integration of IC manufacturing through robotization, artificial intelligence, and cloud computing. Furthermore, the approach eliminates several redundant steps in the synthesis, handling, and disposal of source precursors and their byproducts for CVD, ALD, ALE and other chemically based manufacturing processes, and thus ultimately lowers the manufacturing cost for both conventional and new IC materials. Further, by eliminating the issues associated with precursor thermal, chemical, and pyrophoric instabilities, this new paradigm enables the deposition of a myriad of new thin-film materials and compositions for IC applications that are practically unattainable with existing precursors. Preliminary and planned demonstration examples for the generation and deposition of highly toxic and unstable source precursors are provided.
Low to moderate temperature vapor deposition processes are provided for the deposition of silicon... more Low to moderate temperature vapor deposition processes are provided for the deposition of silicon-based thin films, such as silicon nitride films, silicon carbonitride films, silicon oxide films, and silicon films. The processes includes in a single cycle, heating a substrate to a predetermined temperature; providing a precursor containing an N-alkyl substituted perhydridocyclotrisilazane in the vapor phase to a reaction zone containing the substrate, forming a monolayer of the precursor by adsorption to the substrate surface, and exposing the adsorbed monolayer on the substrate in the reaction zone to a remote or direct soft plasma of a co-reactant. The adsorbed precursor monolayer reacts with the soft plasma and undergoes conversion to a discrete atomic or molecular layer of a silicon-based thin film via dissociation and/or decomposition due to or enabled by a substrate surface-induced process. The cycle is then repeated to form a silicon-based thin film of a desired thickness. keywords: Silicon Nitride; SiN; Organosilicon Chemistry
A new class of compounds known as chalcogenosilacyclopentanes is described. These compounds are f... more A new class of compounds known as chalcogenosilacyclopentanes is described. These compounds are five-membered ring structures containing a silicon-selenium or silicon-tellurium bond, as shown in Formulas (I) and (II). In these compounds, the substituents on the silicon and on the ring carbons may be hydrogen, alkyl, alkoxy, aromatic, or ether groups. The chalcogenosilacyclopentane compounds undergo ring-opening reactions with hydroxyl and other protic functionalities and may be used to prepare substrates that are amenable to thin film deposition techniques such as ALD and CVD.
Journal of Solid State Science and Technology, Apr 3, 2024
Silicon carbide (SiC x) thin films deposition processes fall primarily into three main categories... more Silicon carbide (SiC x) thin films deposition processes fall primarily into three main categories: (1) chemical vapor deposition (CVD) and its variants, including plasma enhanced CVD (PE-CVD); (2) physical vapor deposition (PVD), including various forms of sputtering; (3) alternative (non-CVD and non-PVD) methodologies. Part I of this two-part report ECS J. Solid State Sci. Technol., 12, 103001 (2023) examined recent peer-reviewed publications available in the public domain pertaining to the various CVD processes for SiC x thin films and nanostructures, as well as CVD modeling and mechanistic studies. In Part II, we continue our detailed, systematic review of the latest progress in cutting-edge SiC x thin film innovations, focusing on PVD and other non-PVD and non-CVD SiC x coating technologies. Particular attention is given to pertinent experimental details from PVD and alternative (non-CVD and non-PVD) processing methodologies as well as their influence on resulting film properties and performance. keywords physical vapor deposition; silicon carbide
To provide an integrated system for synthesis of a film-forming precursor, consumption of the pre... more To provide an integrated system for synthesis of a film-forming precursor, consumption of the precursor and formation of a thin film on a substrate.SOLUTION: The integrated system includes a raw material source, a precursor synthesis chamber in communication with the raw material source, a thin film processing chamber in communication with the precursor synthesis chamber for supplying the precursor from the precursor synthesis chamber to the thin film processing chamber in a controlled manner for consumption of the precursor to form the thin film on the substrate, a monitoring system for monitoring of the thin film formation in the thin film processing chamber and/or the precursor synthesis in the precursor synthesis chamber, and a controller for controlling a rate of the precursor synthesis, precursor consumption and/or thin film formation. The rate of precursor synthesis is synchronized with the rate of precursor consumption for formation of the thin film.
ECS Journal of Solid State Science and Technology, 2023
In Part I of a two-part report, we provide a detailed and systematic review of the latest progres... more In Part I of a two-part report, we provide a detailed and systematic review of the latest progress in cutting-edge innovations for the silicon carbide (SiC) material system, focusing on chemical vapor deposition (CVD) thin film technologies. To this end, up-to-date results from both incremental developments in traditional SiC applications as well major advances in novel SiC usages are summarized. Emphasis is placed on new chemical sources for Si and C, particularly in the form of single source SiC precursors as well as emerging molecular and atomic scale deposition techniques, with special attention to their effects on resulting film properties and performance. The review also covers relevant research and development efforts as well as their potential impact on and role in the introduction of new technological applications. Part II will focus on findings for physical vapor deposition (PVD) as well as other deposition techniques.
A method for producing a contact lens having a water contact angle below about 90° involves prepa... more A method for producing a contact lens having a water contact angle below about 90° involves preparing a molding resin comprising a polyether modified polyolefin; forming the molding resin into a mold; preparing a contact lens composition; filling the contact lens composition into the mold; and polymerizing the contact lens composition to form a contact lens. A method of inducing water contact angle below 90° and improved surface wettability of a contact lens involves cast polymerizing a mixture of monomers in a mold formed from a molding resin containing a polyether modified polyolefin to form a contact lens having a water contact angle of less than about 90°. Single-use molds for contact lens manufacture are also provided.
A method for deposition of a cobalt thin film onto a substrate is provided. The method includes p... more A method for deposition of a cobalt thin film onto a substrate is provided. The method includes providing a source precursor containing on or more of elements constituting the thin film generating a transient species from the source precursor and depositing a thin film onto the substrate from the transient species. The transient species being a reactive intermediate that has a limited lifetime in a condensed phase at room temperature.
Large ring silacrown ethers having at least fourteen ring atoms with at least one lipophilic or h... more Large ring silacrown ethers having at least fourteen ring atoms with at least one lipophilic or hydrophobic substituent on the ring and/or on the silicon atom are provided. Pharmaceutical compositions containing these silacrown ethers and the use of these materials as therapeutic agents are also described. Keywords: Ion Channel; channelopathy; macrocycle; ionophore; crown ether; vasodilator; heterocyclic chemistry
A method for forming a fluorinated oxostannate film involves vaporizing a volatile fluorinated al... more A method for forming a fluorinated oxostannate film involves vaporizing a volatile fluorinated alkyltin compound having at least two hydrolytically sensitive functional groups or at least two reactive functional groups which are sensitive to oxidation at a temperature greater than 200° C.; providing a substrate; physisorbing or chemisorbing the fluorinated alkyltin compound onto the substrate; and exposing the physisorbed or chemisorbed fluorinated alkyltin compound to a sequence of hydrolysis, irradiation, and/or oxidation steps to form the fluorinated oxostannate thin film on the substrate. Fluorinated alkyltin compounds having formula (I) are also described, in which Rf is a fluorinated or partially fluorinated linear or branched alkyl group having about 1 to about 5 carbon atoms, X is a dialkylamino group having about 1 to about 4 carbon atoms, and n is 1 or 2: (RfCH2)nSnX(4-n) (I).
Silicon nitride (SiN x , x ∼ 1) thin films were deposited by chemical vapor deposition on silicon... more Silicon nitride (SiN x , x ∼ 1) thin films were deposited by chemical vapor deposition on silicon oxide (SiO 2) substrates by combining controlled pulses of the precursor 1,3,5-tri(isopropyl)cyclotrisilazane (TICZ, C 9 H 27 N 3 Si 3) with a continuous ammonia (NH 3) plasma. This plasma-assisted pulsed CVD (PPCVD) process enables the integration of the nanoscale thickness and uniformity control achieved in atomic layer deposition with the efficiency of plasma-enhanced CVD (PE-CVD). TICZ was selected because it is a nonpyrophoric stable liquid with a high vapor pressure (∼133 Pa at 70°C) and could act as a single source for SiN x with both high Si and N contents. An optimized PPCVD process window was identified consisting of a substrate temperature of 350°C, a TICZ pulse of ≤0.2 s, and a TICZ purge pulse ≥10 s in a continuous direct NH 3 plasma at a NH 3 flow rate and a power of 40 SCCM and 3000 W, respectively. The as-deposited films were analyzed by x-ray photoelectron spectroscopy (XPS) and spectroscopic ellipsometry. XPS analysis confirmed the absence of any C inclusion and demonstrated the existence of the 1:1 Si:N ratio. In situ, real-time ellipsometry measurements indicated that SiN x growth occurred in a typical PE-CVD regime. They also yielded an as-grown SiN x average refractive index of ∼1.75.
Journal of Biomedical Materials Research Part A, Apr 15, 2022
Contact lenses are one of the most successful biomaterials in history with a global market estima... more Contact lenses are one of the most successful biomaterials in history with a global market estimated to be worth over $17 billion in 2025. Silicone hydrogel contact lenses dominate the market and are complex biphasic biomaterials with several critical material properties needed for clinical use. Careful consideration of composition and chemistry is needed to identify formulations of lenses meeting all commercial standards with the potential for improved manufacturability, cost, and/or next generation use. Four silicone macromers were investigated in this work with varying symmetry of siloxane units and macromer structure, number of siloxane groups, branching, length, and concentration. Novel silicone hydrogel lenses were produced and evaluated for optical transmittance, elastic modulus, oxygen transmissibility, water content, and surface wettability. Several lenses met commercial standards and demonstrated an increase in oxygen permeability (Dk) and inverse relationship with elastic modulus and siloxane concentration, respectively. A hydrophobic/hydrophilic ratio below 1.4 was needed for a co‐continuous water phase. Substitution of methoxypropyl groups for butyl groups increased hydrophobic microdomains leading to decreased optical quality and mechanical properties. Generally, fluorine‐containing silicone macromers allowed for a wider range of successful compositions, and above a certain hydrophilic composition, the presence of trifluoropropyl groups resulted in improved solubility and optically clear lenses. Data also showed asymmetric siloxane macromers have potential to meet critical lens properties at lower overall siloxane content. New lens materials with wider composition ranges meeting all clinical lens properties is a significant challenge and may significantly expand the field.
A vapor deposition process is provided for the growth of as-deposited hydrogen-free silicon carbi... more A vapor deposition process is provided for the growth of as-deposited hydrogen-free silicon carbide (SiC) and SiC films including oxygen (SiC:O) thin films. For producing the SiC thin films, the process includes providing a silahydrocarbon precursor, such as TSCH (1,3,5-trisilacyclohexane), in the vapor phase, with or without a diluent gas, to a reaction zone containing a heated substrate, such that adsorption and decomposition of the precursor occurs to form stoichiometric, hydrogen-free, silicon carbide (SiC) in a 1:1 atom ratio between silicon and carbon on the substrate surface without exposure to any other reactive chemical species or co-reactants. For the SiC:O films, an oxygen source is added to the reaction zone to dope the SiC films with oxygen. In the silahydrocarbon precursors, every carbon atom is bonded to two silicon atoms, with each silicon atom being additionally bonded to two or more hydrogen atoms.
Stoichiometric silicon carbide (SiC) thin films were grown using thermal chemical vapor depositio... more Stoichiometric silicon carbide (SiC) thin films were grown using thermal chemical vapor deposition (TCVD) from the single source precursor 1,3,5-trisilacyclohexane (TSCH) on c-Si (100) substrates within an optimized substrate temperature window ranging from 650 to 850°C. X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared spectroscopy (FTIR) analyses revealed that the as-deposited films consisted of a Si-C matrix with a Si:C ratio of ~1:1. FTIR and photoluminescence (PL) spectrometry studies showed that films deposited ≥ 750°C were defect- and H-free within the detection limit of the techniques used, while ellipsometry measurements yielded an as-grown SiC average refractive index of ~2.7, consistent with the reference value for the 3C-SiC phase. The exceptional quality of the films appears sufficient to overcome limitations associated with structural defects ranging from failure in high voltage, high temperature electronics to 2-D film growth. TSCH, a liquid at room temperature with good structural stability during transport and handling as well as high vapor pressure (~10 torr at 25°C), provides a viable single source precursor for the growth of stoichiometric SiC without the need for post-deposition thermal treatment.
A method for deposition of a thin film onto a substrate is provided. The method includes providin... more A method for deposition of a thin film onto a substrate is provided. The method includes providing a source precursor containing on or more of elements constituting the thin film, generating a transient species from the source precursor, and depositing a thin film onto the substrate from the transient species. The transient species being a reactive intermediate that has a limited lifetime in a condensed phase at or above room temperature. An example of epitaxial silicon deposition from the transient intermediate bis(trihydridosilyl)silylene, derived from isotetrasilane, is provided.
Novel N-alkyl substituted perhydridocyclic silazanes, oligomeric N-alkyl perhydridosilazane compo... more Novel N-alkyl substituted perhydridocyclic silazanes, oligomeric N-alkyl perhydridosilazane compounds, and N-alkylaminodihydridohalosilanes, and a method for their synthesis are provided. The novel compounds may be used to form high silicon nitride content films by thermal or plasma induced decomposition. Keywords: Organosilicon; Silicon Nitride; Triisopropylcyclotrisilazane
Increasingly precise control of polymer architectures generated by “Living” Anionic Ring-Opening ... more Increasingly precise control of polymer architectures generated by “Living” Anionic Ring-Opening Polymerization (Living AROP) is leading to a broad range of commercial ad-vanced material applications, particularly in the area of siloxane macromers. While academic reports on such materials remain sparse, a significant portion of the global population interacts with them on a daily basis—in applications including medical devices, microelectronics, food packaging, synthetic leather, release coatings, and pigment dispersions. The primary driver of this increased utilization of siloxane macromers is their ability to incorporate the properties of silicones into organic structures in a balanced manner. Compared to organic polymers, the differentiating properties of silicones—low Tg, hydrophobicity, low surface energy, and high free molal space—logically lend themselves to applications in which low modulus, release, permeability to oxygen and moisture, and tactile interaction are desired. However, their mechanical, structural and processing properties have until recently precluded practical applications. This review presents applications of “Living” AROP derived polymers from the perspective of historical technology development. Applications in which products are produced on a commercial scale—defined as not only offered for sale, but sold on a recurrent basis—are emphasized. Hybrid polymers with intriguing nanoscale morphology and potential applications in photoresist, microcontact printing, biomimetic soft materials, and liquid crystals are also discussed. Previously unreported work by the authors is provided in the context of this review. Keywords: Breathable Films; Block Polymers; Silicones; Double Gyroid; Self-Healing Polymers; Ultra-high Elongation Elastomers; Release Coatings; Photoresists; siloxanes
A thin film deposition process is provided. The process includes, in a single cycle, providing a ... more A thin film deposition process is provided. The process includes, in a single cycle, providing a precursor in the vapor phase with or without a carrier gas to a reaction zone containing a substrate, such that a monolayer of the precursor is adsorbed to a surface of the substrate and the adsorbed monolayer subsequently undergoes conversion to a discrete atomic or molecular layer of a thin film, without any intervening pulse of or exposure to other chemical species or co-reactants. keywords: semiconductor fabrication; vapor deposition; cobalt
Results are presented from an exploratory study of near-room-temperature pulsed deposition of SiC... more Results are presented from an exploratory study of near-room-temperature pulsed deposition of SiCxNy thin films using 1,3,5-tri(isopropyl)cyclotrisilazane (TICZ, C9H27N3Si3) and soft remote ammonia (NH3) plasma co-reactants. The process involved four pulses: thermal adsorption of TICZ to the substrate at very low temperature, nitrogen (N2) purge, soft NH3 remote plasma step, and N2 purge. These steps were repeated until the desired film thickness was reached. The ratio of C to N in the films was modulated by controlling the substrate temperature in the range of 30 to 200° C. In-situ analysis of the deposition process was carried-out using spectroscopic ellipsometry, and the films were 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 optimum low energy environment for the controlled deposition of SiCxNy protective coatings on thermally fragile, chemically sensitive substrates, including plastics and polymers. key words: silicon carbonitride; thin films
High-quality silicon nitride (SiN x) thin films were grown by remote-plasma-activated pulsed chem... more High-quality silicon nitride (SiN x) thin films were grown by remote-plasma-activated pulsed chemical vapor deposition (P-CVD) from the source precursor 1,3,5-tri(isopropyl)cyclotrisilazane (TICZ, C 9 H 27 N 3 Si 3) and remote ammonia (NH 3) plasma on silicon oxide (SiO 2) substrates within an optimized substrate temperature window ranging from 200 to 350 °C. TICZ was selected because of its chemical stability, non-pyrophoric nature, good vapor pressure (~127 Pa at 70 °C), and its chemical structure that incorporates alkyl groups with three C atoms on each N atom, which provides a clean elimination mechanism for low temperature SiN x deposition. P-CVD consisted of a four-step process: TICZ pulse with no plasma, N 2 purge, NH 3 plasma pulse, and N 2 purge. The as-deposited films were analyzed using spectroscopic ellipsometry and x-ray photoelectron spectroscopy (XPS). Wet etch rates were determined using a standard solution consisting of 0.5% hydrofluoric acid in deionized water. XPS analysis revealed a Si:N ratio of ~1:1 within the entire substrate temperature range and validated the formation of the SiN x phase. In situ, real-time ellipsometry measurements confirmed that SiN x growth exhibited a non-self-limiting P-CVD behavior. They also yielded an as-grown SiN x average refractive index of ~1.8 for the films grown at substrate temperatures above 200 °C.
The semiconductor industry is being radically impacted by the placing of greater emphasis on the ... more The semiconductor industry is being radically impacted by the placing of greater emphasis on the development of hetero-devices and systems that will act as essential drivers for a wide spectrum of technological applications. The introduction of new materials and their integration with currently used materials are projected to replace integrated circuitry (IC) design and device scaling as the key enablers to the realization of improved device performance and larger density gains. Yet material selection has been constrained by existing fabrication process technology. To date, fabrication processes have dictated material selection by limiting chemical sources or precursors to those that match existing process tools associated with chemically based vapor phase processes and their variants, which in turn limits material compositions in ICs. The processing and integration of new materials compositions and structures will require the introduction of new deposition and etching processes, and manufacturing worthy tool designs and associated protocols that provide new methods for atomic-level control. To this end, a novel manufacturing paradigm is presented comprising a method and system for real-time, closed-loop monitoring and control of synthesis, supply, and consumption of precursors in process intensification techniques including chemical vapor deposition (CVD), atomic layer deposition (ALD), atomic layer etching (ALE), and other IC manufacturing processes. This intelligent automated manufacturing approach is consistent with a central component of the semiconductor industry’s recent adoption of Industry 4.0., including vertical integration of IC manufacturing through robotization, artificial intelligence, and cloud computing. Furthermore, the approach eliminates several redundant steps in the synthesis, handling, and disposal of source precursors and their byproducts for CVD, ALD, ALE and other chemically based manufacturing processes, and thus ultimately lowers the manufacturing cost for both conventional and new IC materials. Further, by eliminating the issues associated with precursor thermal, chemical, and pyrophoric instabilities, this new paradigm enables the deposition of a myriad of new thin-film materials and compositions for IC applications that are practically unattainable with existing precursors. Preliminary and planned demonstration examples for the generation and deposition of highly toxic and unstable source precursors are provided.
Low to moderate temperature vapor deposition processes are provided for the deposition of silicon... more Low to moderate temperature vapor deposition processes are provided for the deposition of silicon-based thin films, such as silicon nitride films, silicon carbonitride films, silicon oxide films, and silicon films. The processes includes in a single cycle, heating a substrate to a predetermined temperature; providing a precursor containing an N-alkyl substituted perhydridocyclotrisilazane in the vapor phase to a reaction zone containing the substrate, forming a monolayer of the precursor by adsorption to the substrate surface, and exposing the adsorbed monolayer on the substrate in the reaction zone to a remote or direct soft plasma of a co-reactant. The adsorbed precursor monolayer reacts with the soft plasma and undergoes conversion to a discrete atomic or molecular layer of a silicon-based thin film via dissociation and/or decomposition due to or enabled by a substrate surface-induced process. The cycle is then repeated to form a silicon-based thin film of a desired thickness. keywords: Silicon Nitride; SiN; Organosilicon Chemistry
A new class of compounds known as chalcogenosilacyclopentanes is described. These compounds are f... more A new class of compounds known as chalcogenosilacyclopentanes is described. These compounds are five-membered ring structures containing a silicon-selenium or silicon-tellurium bond, as shown in Formulas (I) and (II). In these compounds, the substituents on the silicon and on the ring carbons may be hydrogen, alkyl, alkoxy, aromatic, or ether groups. The chalcogenosilacyclopentane compounds undergo ring-opening reactions with hydroxyl and other protic functionalities and may be used to prepare substrates that are amenable to thin film deposition techniques such as ALD and CVD.
Journal of Solid State Science and Technology, Apr 3, 2024
Silicon carbide (SiC x) thin films deposition processes fall primarily into three main categories... more Silicon carbide (SiC x) thin films deposition processes fall primarily into three main categories: (1) chemical vapor deposition (CVD) and its variants, including plasma enhanced CVD (PE-CVD); (2) physical vapor deposition (PVD), including various forms of sputtering; (3) alternative (non-CVD and non-PVD) methodologies. Part I of this two-part report ECS J. Solid State Sci. Technol., 12, 103001 (2023) examined recent peer-reviewed publications available in the public domain pertaining to the various CVD processes for SiC x thin films and nanostructures, as well as CVD modeling and mechanistic studies. In Part II, we continue our detailed, systematic review of the latest progress in cutting-edge SiC x thin film innovations, focusing on PVD and other non-PVD and non-CVD SiC x coating technologies. Particular attention is given to pertinent experimental details from PVD and alternative (non-CVD and non-PVD) processing methodologies as well as their influence on resulting film properties and performance. keywords physical vapor deposition; silicon carbide
To provide an integrated system for synthesis of a film-forming precursor, consumption of the pre... more To provide an integrated system for synthesis of a film-forming precursor, consumption of the precursor and formation of a thin film on a substrate.SOLUTION: The integrated system includes a raw material source, a precursor synthesis chamber in communication with the raw material source, a thin film processing chamber in communication with the precursor synthesis chamber for supplying the precursor from the precursor synthesis chamber to the thin film processing chamber in a controlled manner for consumption of the precursor to form the thin film on the substrate, a monitoring system for monitoring of the thin film formation in the thin film processing chamber and/or the precursor synthesis in the precursor synthesis chamber, and a controller for controlling a rate of the precursor synthesis, precursor consumption and/or thin film formation. The rate of precursor synthesis is synchronized with the rate of precursor consumption for formation of the thin film.
ECS Journal of Solid State Science and Technology, 2023
In Part I of a two-part report, we provide a detailed and systematic review of the latest progres... more In Part I of a two-part report, we provide a detailed and systematic review of the latest progress in cutting-edge innovations for the silicon carbide (SiC) material system, focusing on chemical vapor deposition (CVD) thin film technologies. To this end, up-to-date results from both incremental developments in traditional SiC applications as well major advances in novel SiC usages are summarized. Emphasis is placed on new chemical sources for Si and C, particularly in the form of single source SiC precursors as well as emerging molecular and atomic scale deposition techniques, with special attention to their effects on resulting film properties and performance. The review also covers relevant research and development efforts as well as their potential impact on and role in the introduction of new technological applications. Part II will focus on findings for physical vapor deposition (PVD) as well as other deposition techniques.
A method for producing a contact lens having a water contact angle below about 90° involves prepa... more A method for producing a contact lens having a water contact angle below about 90° involves preparing a molding resin comprising a polyether modified polyolefin; forming the molding resin into a mold; preparing a contact lens composition; filling the contact lens composition into the mold; and polymerizing the contact lens composition to form a contact lens. A method of inducing water contact angle below 90° and improved surface wettability of a contact lens involves cast polymerizing a mixture of monomers in a mold formed from a molding resin containing a polyether modified polyolefin to form a contact lens having a water contact angle of less than about 90°. Single-use molds for contact lens manufacture are also provided.
A method for deposition of a cobalt thin film onto a substrate is provided. The method includes p... more A method for deposition of a cobalt thin film onto a substrate is provided. The method includes providing a source precursor containing on or more of elements constituting the thin film generating a transient species from the source precursor and depositing a thin film onto the substrate from the transient species. The transient species being a reactive intermediate that has a limited lifetime in a condensed phase at room temperature.
Large ring silacrown ethers having at least fourteen ring atoms with at least one lipophilic or h... more Large ring silacrown ethers having at least fourteen ring atoms with at least one lipophilic or hydrophobic substituent on the ring and/or on the silicon atom are provided. Pharmaceutical compositions containing these silacrown ethers and the use of these materials as therapeutic agents are also described. Keywords: Ion Channel; channelopathy; macrocycle; ionophore; crown ether; vasodilator; heterocyclic chemistry
A method for forming a fluorinated oxostannate film involves vaporizing a volatile fluorinated al... more A method for forming a fluorinated oxostannate film involves vaporizing a volatile fluorinated alkyltin compound having at least two hydrolytically sensitive functional groups or at least two reactive functional groups which are sensitive to oxidation at a temperature greater than 200° C.; providing a substrate; physisorbing or chemisorbing the fluorinated alkyltin compound onto the substrate; and exposing the physisorbed or chemisorbed fluorinated alkyltin compound to a sequence of hydrolysis, irradiation, and/or oxidation steps to form the fluorinated oxostannate thin film on the substrate. Fluorinated alkyltin compounds having formula (I) are also described, in which Rf is a fluorinated or partially fluorinated linear or branched alkyl group having about 1 to about 5 carbon atoms, X is a dialkylamino group having about 1 to about 4 carbon atoms, and n is 1 or 2: (RfCH2)nSnX(4-n) (I).
Silicon nitride (SiN x , x ∼ 1) thin films were deposited by chemical vapor deposition on silicon... more Silicon nitride (SiN x , x ∼ 1) thin films were deposited by chemical vapor deposition on silicon oxide (SiO 2) substrates by combining controlled pulses of the precursor 1,3,5-tri(isopropyl)cyclotrisilazane (TICZ, C 9 H 27 N 3 Si 3) with a continuous ammonia (NH 3) plasma. This plasma-assisted pulsed CVD (PPCVD) process enables the integration of the nanoscale thickness and uniformity control achieved in atomic layer deposition with the efficiency of plasma-enhanced CVD (PE-CVD). TICZ was selected because it is a nonpyrophoric stable liquid with a high vapor pressure (∼133 Pa at 70°C) and could act as a single source for SiN x with both high Si and N contents. An optimized PPCVD process window was identified consisting of a substrate temperature of 350°C, a TICZ pulse of ≤0.2 s, and a TICZ purge pulse ≥10 s in a continuous direct NH 3 plasma at a NH 3 flow rate and a power of 40 SCCM and 3000 W, respectively. The as-deposited films were analyzed by x-ray photoelectron spectroscopy (XPS) and spectroscopic ellipsometry. XPS analysis confirmed the absence of any C inclusion and demonstrated the existence of the 1:1 Si:N ratio. In situ, real-time ellipsometry measurements indicated that SiN x growth occurred in a typical PE-CVD regime. They also yielded an as-grown SiN x average refractive index of ∼1.75.
Journal of Biomedical Materials Research Part A, Apr 15, 2022
Contact lenses are one of the most successful biomaterials in history with a global market estima... more Contact lenses are one of the most successful biomaterials in history with a global market estimated to be worth over $17 billion in 2025. Silicone hydrogel contact lenses dominate the market and are complex biphasic biomaterials with several critical material properties needed for clinical use. Careful consideration of composition and chemistry is needed to identify formulations of lenses meeting all commercial standards with the potential for improved manufacturability, cost, and/or next generation use. Four silicone macromers were investigated in this work with varying symmetry of siloxane units and macromer structure, number of siloxane groups, branching, length, and concentration. Novel silicone hydrogel lenses were produced and evaluated for optical transmittance, elastic modulus, oxygen transmissibility, water content, and surface wettability. Several lenses met commercial standards and demonstrated an increase in oxygen permeability (Dk) and inverse relationship with elastic modulus and siloxane concentration, respectively. A hydrophobic/hydrophilic ratio below 1.4 was needed for a co‐continuous water phase. Substitution of methoxypropyl groups for butyl groups increased hydrophobic microdomains leading to decreased optical quality and mechanical properties. Generally, fluorine‐containing silicone macromers allowed for a wider range of successful compositions, and above a certain hydrophilic composition, the presence of trifluoropropyl groups resulted in improved solubility and optically clear lenses. Data also showed asymmetric siloxane macromers have potential to meet critical lens properties at lower overall siloxane content. New lens materials with wider composition ranges meeting all clinical lens properties is a significant challenge and may significantly expand the field.
A vapor deposition process is provided for the growth of as-deposited hydrogen-free silicon carbi... more A vapor deposition process is provided for the growth of as-deposited hydrogen-free silicon carbide (SiC) and SiC films including oxygen (SiC:O) thin films. For producing the SiC thin films, the process includes providing a silahydrocarbon precursor, such as TSCH (1,3,5-trisilacyclohexane), in the vapor phase, with or without a diluent gas, to a reaction zone containing a heated substrate, such that adsorption and decomposition of the precursor occurs to form stoichiometric, hydrogen-free, silicon carbide (SiC) in a 1:1 atom ratio between silicon and carbon on the substrate surface without exposure to any other reactive chemical species or co-reactants. For the SiC:O films, an oxygen source is added to the reaction zone to dope the SiC films with oxygen. In the silahydrocarbon precursors, every carbon atom is bonded to two silicon atoms, with each silicon atom being additionally bonded to two or more hydrogen atoms.
Stoichiometric silicon carbide (SiC) thin films were grown using thermal chemical vapor depositio... more Stoichiometric silicon carbide (SiC) thin films were grown using thermal chemical vapor deposition (TCVD) from the single source precursor 1,3,5-trisilacyclohexane (TSCH) on c-Si (100) substrates within an optimized substrate temperature window ranging from 650 to 850°C. X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared spectroscopy (FTIR) analyses revealed that the as-deposited films consisted of a Si-C matrix with a Si:C ratio of ~1:1. FTIR and photoluminescence (PL) spectrometry studies showed that films deposited ≥ 750°C were defect- and H-free within the detection limit of the techniques used, while ellipsometry measurements yielded an as-grown SiC average refractive index of ~2.7, consistent with the reference value for the 3C-SiC phase. The exceptional quality of the films appears sufficient to overcome limitations associated with structural defects ranging from failure in high voltage, high temperature electronics to 2-D film growth. TSCH, a liquid at room temperature with good structural stability during transport and handling as well as high vapor pressure (~10 torr at 25°C), provides a viable single source precursor for the growth of stoichiometric SiC without the need for post-deposition thermal treatment.
A method for deposition of a thin film onto a substrate is provided. The method includes providin... more A method for deposition of a thin film onto a substrate is provided. The method includes providing a source precursor containing on or more of elements constituting the thin film, generating a transient species from the source precursor, and depositing a thin film onto the substrate from the transient species. The transient species being a reactive intermediate that has a limited lifetime in a condensed phase at or above room temperature. An example of epitaxial silicon deposition from the transient intermediate bis(trihydridosilyl)silylene, derived from isotetrasilane, is provided.
Novel N-alkyl substituted perhydridocyclic silazanes, oligomeric N-alkyl perhydridosilazane compo... more Novel N-alkyl substituted perhydridocyclic silazanes, oligomeric N-alkyl perhydridosilazane compounds, and N-alkylaminodihydridohalosilanes, and a method for their synthesis are provided. The novel compounds may be used to form high silicon nitride content films by thermal or plasma induced decomposition. Keywords: Organosilicon; Silicon Nitride; Triisopropylcyclotrisilazane
Increasingly precise control of polymer architectures generated by “Living” Anionic Ring-Opening ... more Increasingly precise control of polymer architectures generated by “Living” Anionic Ring-Opening Polymerization (Living AROP) is leading to a broad range of commercial ad-vanced material applications, particularly in the area of siloxane macromers. While academic reports on such materials remain sparse, a significant portion of the global population interacts with them on a daily basis—in applications including medical devices, microelectronics, food packaging, synthetic leather, release coatings, and pigment dispersions. The primary driver of this increased utilization of siloxane macromers is their ability to incorporate the properties of silicones into organic structures in a balanced manner. Compared to organic polymers, the differentiating properties of silicones—low Tg, hydrophobicity, low surface energy, and high free molal space—logically lend themselves to applications in which low modulus, release, permeability to oxygen and moisture, and tactile interaction are desired. However, their mechanical, structural and processing properties have until recently precluded practical applications. This review presents applications of “Living” AROP derived polymers from the perspective of historical technology development. Applications in which products are produced on a commercial scale—defined as not only offered for sale, but sold on a recurrent basis—are emphasized. Hybrid polymers with intriguing nanoscale morphology and potential applications in photoresist, microcontact printing, biomimetic soft materials, and liquid crystals are also discussed. Previously unreported work by the authors is provided in the context of this review. Keywords: Breathable Films; Block Polymers; Silicones; Double Gyroid; Self-Healing Polymers; Ultra-high Elongation Elastomers; Release Coatings; Photoresists; siloxanes
A thin film deposition process is provided. The process includes, in a single cycle, providing a ... more A thin film deposition process is provided. The process includes, in a single cycle, providing a precursor in the vapor phase with or without a carrier gas to a reaction zone containing a substrate, such that a monolayer of the precursor is adsorbed to a surface of the substrate and the adsorbed monolayer subsequently undergoes conversion to a discrete atomic or molecular layer of a thin film, without any intervening pulse of or exposure to other chemical species or co-reactants. keywords: semiconductor fabrication; vapor deposition; cobalt
Results are presented from an exploratory study of near-room-temperature pulsed deposition of SiC... more Results are presented from an exploratory study of near-room-temperature pulsed deposition of SiCxNy thin films using 1,3,5-tri(isopropyl)cyclotrisilazane (TICZ, C9H27N3Si3) and soft remote ammonia (NH3) plasma co-reactants. The process involved four pulses: thermal adsorption of TICZ to the substrate at very low temperature, nitrogen (N2) purge, soft NH3 remote plasma step, and N2 purge. These steps were repeated until the desired film thickness was reached. The ratio of C to N in the films was modulated by controlling the substrate temperature in the range of 30 to 200° C. In-situ analysis of the deposition process was carried-out using spectroscopic ellipsometry, and the films were 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 optimum low energy environment for the controlled deposition of SiCxNy protective coatings on thermally fragile, chemically sensitive substrates, including plastics and polymers. key words: silicon carbonitride; thin films
High-quality silicon nitride (SiN x) thin films were grown by remote-plasma-activated pulsed chem... more High-quality silicon nitride (SiN x) thin films were grown by remote-plasma-activated pulsed chemical vapor deposition (P-CVD) from the source precursor 1,3,5-tri(isopropyl)cyclotrisilazane (TICZ, C 9 H 27 N 3 Si 3) and remote ammonia (NH 3) plasma on silicon oxide (SiO 2) substrates within an optimized substrate temperature window ranging from 200 to 350 °C. TICZ was selected because of its chemical stability, non-pyrophoric nature, good vapor pressure (~127 Pa at 70 °C), and its chemical structure that incorporates alkyl groups with three C atoms on each N atom, which provides a clean elimination mechanism for low temperature SiN x deposition. P-CVD consisted of a four-step process: TICZ pulse with no plasma, N 2 purge, NH 3 plasma pulse, and N 2 purge. The as-deposited films were analyzed using spectroscopic ellipsometry and x-ray photoelectron spectroscopy (XPS). Wet etch rates were determined using a standard solution consisting of 0.5% hydrofluoric acid in deionized water. XPS analysis revealed a Si:N ratio of ~1:1 within the entire substrate temperature range and validated the formation of the SiN x phase. In situ, real-time ellipsometry measurements confirmed that SiN x growth exhibited a non-self-limiting P-CVD behavior. They also yielded an as-grown SiN x average refractive index of ~1.8 for the films grown at substrate temperatures above 200 °C.
The background for development of heterosilacyclopentanes (cyclic azasilanes, cyclic thiasilanes)... more The background for development of heterosilacyclopentanes (cyclic azasilanes, cyclic thiasilanes) and examples of single molecule orthogonal double-click chemistry using them for optical coatings and biomedical applications are presented.
A new silicon nitride precursor: TICZ is presented. Salient features are: No Si-C bonds, which te... more A new silicon nitride precursor: TICZ is presented. Salient features are: No Si-C bonds, which tend to increase carbon content Readily decomposed (propene leaving group, ring opening reaction) Scalable synthesis (confirmed) Sufficiently volatile and stable Deposition parameters can be controlled to produce SiN or SIC:N
20th International Symposium on Silicon Chemistry (ISOS-20), 2024
There are over 100 known channelopathy diseases which are generally described as diseases associa... more There are over 100 known channelopathy diseases which are generally described as diseases associated with transport of ions across cell membranes. They include cardiovascular, degenerative neuropathy and renal diseases. For the most part channelopathy diseases have been considered "undruggable." Crown ethers have been shown to have physiological effects ascribed to their ionophoric properties. However, high levels of toxicity precluded interest in evaluation as therapeutics. We prepared silacrown analogs of crown ethers. Our initial studies focused on examples of large ring silacrown ethers having at least fourteen ring atoms with at least one lipophilic or hydrophobic substituent on the ring and/or on the silicon atom are provided. The synthesis of silacrown ethers, ionophoric behavior, preliminary toxicity studies, evaluation in human and rabbit atrial tissue and preliminary studies in cardiac myocyte cell lines will be presented and compared to their carbon analogs. For HL-1 cells, an atrial muscle cell line, three different responses were observed for the compounds tested: no effect on Ca +2 or response to KCl-depolarization, strong inhibition of Ca +2 transients with some residual response to KCl-depolarization, and inhibition of Ca +2 transients and no subsequent response to KCl-depolarization.
ISOS-20 International Symposium on Silicon Chemistry, 2024
The semiconductor industry is being radically impacted by the development of hetero-devices and s... more The semiconductor industry is being radically impacted by the development of hetero-devices and systems for a wide spectrum of technological applications that are drivers for new materials and decreasing form factors. Material selection has been constrained by existing fabrication process technology, limiting chemical sources or precursors to those that match existing CVD and ALD associated processes. Processing and integration of material structures will require the introduction of novel chemistry and deposition processes, and manufacturing worthy protocols that provide new methods for atomic level control of near-zero-thickness thin films. Potential processes and precursors that embody this strategy include: • P-CVD SiNx: This process combines precursor thermal adsorption and the reaction with remote plasma ammonia. A demonstration is presented in which thermal adsorption of tri(isopropyl)cyclotrisilazane (TICZ) ensures a substrate driven nucleation and growth process that leads ultimately to conformal SiNx in extremely high aspect ratio structures. Concurrently, the application of a remote NH3 plasma eliminates any undesirable plasma-induced effects. • ALD and CVD Through Vapor Phase Transient Species Generation: The discrete generation of disilylsilylene as a transient species in physical and energetic environments distinct from the substrate deposition and the parent precursor supply will be discussed. This process enables the deposition of epitaxial silicon films in lower thermal or energetic substrate environments. It also enables the deposition of films with greater conformality. • Integrated Synthesis and Deposition (ISD): A manufacturing paradigm comprising a method and system for real-time, closed-loop synthesis, supply, and consumption of precursors in IC manufacturing processes. In its simplest form, the system consists of a precursor synthesis chamber being physically interfaced with a thin film processing chamber, with precursor being synthesized on demand and supplied into the thin film processing chamber where it is consumed. This allows highly reactive chemistry that would be considered otherwise unacceptable due to explosive or toxicity concerns. • Area Specific Deposition by Topmost Atomic Layer Modification and Restructuring (ASD-TLM): The selective deposition of dielectric or conducting films enabled by molecular layer deposition (MLD) or self-assembled monolayers (SAMs) will be discussed. Trihydridosilanes can be grafted without catalyst to amorphous hydrogenated silicon, gold and titanium substrates. The mechanism involves dissociative adsorption and dehydrocoupling.
Elastomers with exceptionally high elongation prepared by "living" anionic ring-opening polymeriz... more Elastomers with exceptionally high elongation prepared by "living" anionic ring-opening polymerization are described. Background information on polysiloxane AROP used to produce macromers and heterobifunctional polymers is described. The use of these materials for applications ranging from silicone hydrogel contact lenses to elastomers with elongations approaching 5000% are presented.
The semiconductor industry is being radically impacted by placing greater emphasis on the develop... more The semiconductor industry is being radically impacted by placing greater emphasis on the development of hetero-devices and systems that will act as essential drivers for a wide spectrum of technological applications across multiple industrial sectors. The introduction of new materials and their integration with currently used materials are projected to replace IC design and device scaling as the key enablers to the realization of improved device performance and larger density gains. Yet material selection has been constrained by existing fabrication process technology. To date, fabrication processes have dictated material selection by limiting chemical sources or precursors to those that match existing process tools associated with CVD and ALD and their variants, which in turn limits material compositions in ICs. The processing and integration of new materials structures will require the introduction of new deposition and etching processes, and manufacturing worthy protocols that provide new methods for atomic level control. This presentation explores four new such processes and protocols that match these requirements, namely: • P-CVD SiNx: This process combines precursor thermal adsorption with the reaction with remote plasma ammonia. A demonstration is presented in which thermal adsorption of tri(isopropyl)cyclotrisilazane (TICZ) ensures a substrate driven nucleation and growth process that leads ultimately to conformal SiNx in extremely high aspect ratio structures. Concurrently, the application of a remote NH3 plasma eliminates any undesirable plasma-induced effects on the substrate and growing film. • Single Pulse CVD/ALD: These are methods for pulsed deposition of thin films that offer significant reduction in the time to generate thin films by eliminating a number of the steps required in growth cycles. In the case of ALD, for instance, it reduces the number of steps required to grow every individual thin film layer from four to one, thus maximizing process efficiency and wafer throughput, and leading to competitive manufacturing cost of ownership and return on investment. The deposition of high quality cobalt films from cobalt tricarbonyl nitrosyl will be discussed in this context. • Vapor Phase Transient Species Deposition. The discrete generation of transient species under conditions distinct from the substrate and the parent precursor will be discussed. This process enables the deposition of films in lower thermal or energetic substrate environments. It also enables the deposition of films at lower temperatures and ensures greater conformality of the deposited films, allowing film deposition on thermally or chemically fragile substrates. • Integrated Synthesis and Deposition (ISD): A manufacturing paradigm comprising a method and system for real-time, closed-loop synthesis, supply, and consumption of precursors in IC manufacturing processes. In its simplest form, the system consists of a precursor synthesis chamber being physically interfaced with a thin film processing chamber, with precursor being synthesized on demand and supplied in a controlled fashion into the thin film processing chamber where it is consumed in the manufacturing process. This allows practical methods to employ highly reactive chemistry that otherwise could lead to explosive or highly toxic releases.
The demand for surface modified and functionalized nanoparticles, nanopowders and nanocrystals is... more The demand for surface modified and functionalized nanoparticles, nanopowders and nanocrystals is greater than ever. There is a continued effort to improve the performance of nanoparticles that are used in a variety of thermoplastic applications with a primary focus in biomedical, medical, ceramic, aerospace, electronic, and semiconductor. A new class of compounds has been synthesized to maximize bonding efficiency, while optimizing performance in an environmentally friendly manner. Cyclic Azasilanes can be reacted with a variety of hydroxyl laden nanoparticles through a ring-opening reaction that is thermodynamically driven without the formation of volatile byproducts. Cyclic Azasilanes offer a higher level of monolayer deposition compared to traditional organosilane and metal-organic chemistries. They find utility as coupling agents, surface modifiers and functionalizers.
International Society for Contact Lens Research (ISCLR), Aug 22, 2019
An overview of the evolution of siloxane polymers to meet the demands of silicone hydrogels is pr... more An overview of the evolution of siloxane polymers to meet the demands of silicone hydrogels is presented. Structural design of siloxane monomers and macromers as related to oxygen permeability, optical clarity, wettability, and mechanical properties is described.
A study of hydrophilic silanes as a means to improve pigment wetting and dispersion in water-base... more A study of hydrophilic silanes as a means to improve pigment wetting and dispersion in water-based color cosmetics including new amino acid modified silanes. Correlation of objective measurements to performance attributes are discussed.
243rd American Chemical Society National Meeting, 2012
Siloxane macromers and macromolecular engineering for elastomer and dendrimer synthesis are prese... more Siloxane macromers and macromolecular engineering for elastomer and dendrimer synthesis are presented.
International Symposium on Silicon Chemistry ISOS XVII, 2014
The synthesis and effectiveness of a fixed-bed hydroxylation catalyst complex that includes (i) a... more The synthesis and effectiveness of a fixed-bed hydroxylation catalyst complex that includes (i) a metal carbene catalyst, wherein the metal is platinum, and (ii) a catalyst support that includes one or more of silica, alumina and/or glass is described. Hydrosilyation products using this chemistry have low color, high isomeric yield and allow recovery and re-use of active platinum.
American Chemical Society Abstracts (252nd Meeting), 2016
Thermoplastic composites have transformed everyday life. Portable tools, appliances and business ... more Thermoplastic composites have transformed everyday life. Portable tools, appliances and business machine housings in thousands of applications are the the design engineers materials of choice. This presentation overviews the innovations made during the period of time in the '60s and '70s at LNP Engineering Plastics that spear-headed much of the development both technologically and by the cluster of companies started by former LNP employees. This presentation is a brief documentation of the challenges and development of engineering thermoplastic composites- including glass fiber and carbon fiber reinforcement systems with examples of applications in which there was early adoption of the new materials. It is a case history of business growth from concept to the creation of a multi-billion dollar industry.
PREP 2015, 28th International Symposium on Preparative and Process Chromatography, 2015
Dipodal silanes have two silicon atoms which can bond covalently through oxane bridges to a surfa... more Dipodal silanes have two silicon atoms which can bond covalently through oxane bridges to a surface. Dipodal silanes offer a distinctive advantage over conventional silanes, which possess only one silicon atom, in their ability to maintain the integrity of surface coatings in aggressive aqueous environments. This is important in applications in biotechnology, and particularly in separation science where long-term performance in aqueous environments is critical. Recently, dipodal silanes with "pendant" rather than "bridged" structures have been introduced. Bridged dipodal silanes substitute silicon atoms in alpha and omega positions of an organic moiety, while pendant dipodal silanes typically have silicon atoms separated by by two carbons and an organic moiety that in principle can extend outward from a modified surface. Significantly, in neutral, saline and highly acidic environments, pendant dipodal silanes clearly demonstrate improved resistance to hydrolysis compared to both conventional silanes and bridged dipodal silanes. New data shows that pendant dipodal silanes in which there is only one carbon separation between the silicon atoms have exceptional hydrolytic stability making them candidates for prep-scale chromatography where protocols require stability and reproducibilty.
22nd International Conference on Atomic Layer Deposition (ASD 2022), 2022
Self-assembled monolayers (SAMs) formed or modified by rapid "click" chemical reactions are recei... more Self-assembled monolayers (SAMs) formed or modified by rapid "click" chemical reactions are receiving significant attention due to their demonstrated ability to promote or facilitate area-specific or area-selective deposition utilizing processes that occur on time scales compatible with high-throughput manufacture and cyclic deposition schemes. By precision tailoring of the chemical structure of the SAM layer, the selectivity and speed of the reactions with both the underlying substrate and subsequent deposition cycles can be enhanced in order to provide rapid, selective processes with few or no chemical byproducts. In this work we demonstrate that cyclic azasilanes and cyclic thiasilanes can rapidly bond to the surface of hydroxyl-covered substrates in the vapor phase, with saturated coverage being reached in several seconds in a manufacturing-worthy atomic layer deposition tool. The effects of processing parameters, including pulse time, temperature, substrate type, and pre-treatment on the deposition profile, as well as the subsequent reactivity of cyclic azasilanes to further modify the chemical nature of the surface are discussed, with an emphasis on rapid "click" chemical processes compatible with high throughput. It was observed that on hydroxyl (OH)-terminated surfaces such as silicon native or thermal oxide the cyclic silanes reach a saturation point in approximately five seconds under typical ALD conditions over the temperature range of 30 °C to 300 °C, as determined by water contact angle and ellipsometry. The reactivity and selectivity of cyclic azasilanes to other oxide surfaces as well as non-oxides such as copper, silicon nitride, and HF-etched silicon will be discussed, as will process to remove azasilane monolayers after deposition.
The identification of viable diffusion barrier/adhesion promoter material and associated depositi... more The identification of viable diffusion barrier/adhesion promoter material and associated deposition processes is a critical factor in the successful development of structurally and electrically reliable copper based metallization schemes. As feature sizes continue shrinking, such materials are expected to delivery enhanced performance at increasingly thinner layers to allow maximum space utilization by the actual conductor. In this respect, Ta and W based binary and ternary nitrides present promising solutions in view of their hardness, chemical inertness, and thermal stability to high temperatures. Additionally, their availability in amorphous form provides the added benefit of inherent absence of grain boundaries, which usually serve as a primary diffusion path. This paper presents finds from the development of low-temperature (,350°C) CVD processes for the growth of ultrathin Ta, W, Ta-Si, and WSinitride layers for sub−0.18 micron device structures. These processes employ novel inorganic and metal-organic source precursors which allow for the in-situ, one-step, growth of binary and ternary nitrides from appropriate mixtures of the corresponding source precursors. Results will also be discussed from diffusion barrier studies which established performance metris for the applicability of such materials in copper interconnect technologies.
11th International Workshop on Silicone Polymers 2017, 2017
Cyclic azasilanes have been synthesized for the purpose of developing coupling agents appropriate... more Cyclic azasilanes have been synthesized for the purpose of developing coupling agents appropriate for a variety of nanotechnologies including surface modification of nanoparticles, nanocrystals, mesoporous materials and substrates. Cyclic azasilanes contain cryptic amine functionality that can perform a coupling reaction with functional molecules after the surface-initiated ring-opening reaction, allowing for a one-pot self-assembly route on nanostructures. Activated silanes are blends of cyclic azasilanes with conventional silanes that provide high-speed reactivity induced by surfaces, unlike conventional silanes that require moisture for initiation. In epoxy resin systems, activated silanes with amine functionality give the benefits of moisture-free deposition, high speed reactivity, adhesion promotion, and high bond strengths between substrates. The kinetics and mechanism of cure, as well as mechanical bond strength between a variety of substrates will be investigated for a series of activated silane formulations.
Advances for Silicon Chemistry are presented for 2004. Plenary and invited Lectures
J.E. Mark ... more Advances for Silicon Chemistry are presented for 2004. Plenary and invited Lectures
J.E. Mark Some Interesting Things about the Polysiloxanes; R.G. Nuzzo Micro, Nano, Macro: silico, Silicones and Soft-Lithography Off Road on the Road Map; I. Yilgor, E. Yilgor New Generation of Silicone-Urea Elastomers; M. J. Sailor Smart Dust: Photonic Crystals Derived from Nanocrystalline Porous Silicon; T. D. Tilley Participation of Ligand Alpha-Substituents in Bond Activations and Catalytic Transformations Involving Silicon; L. Rosenberg Catalytic Si-H Activation in the Synthesis and Modification of Organosilanes; I. N. Jung Dehydrogenative Double Silylation of Acetylenes; J. L. Leighton Straines Silacycles: A Powerful Platform for Asymmetric Reaction Design; U, Wiesner Polymer Approaches to Silicn Based Nanostructured Hybrid Materials; E. Liskola Molecular Control of Interface Chemistry by Atomic Layer Deposition (ALD); C. Strohmann About the Stereochemistry of Lithiated Silanes; V.S.-Y. Lin Gatekeeping Effect: Synthesis of Multi-functionalized Mesoporous Silica Nanospheres; R, West The Radical Chemistry of Stable Silylenes; R. Walsh What we have Learnes About the Stabilities Of Silarane; A. Sekiguchi Stable Disilyne with a Silicon-Silicon Triple Bond; S. Rubisztajn New Condensation Process Leading to the Formation of Siloxane Bonds; A. Basindale, P. Lickiss Colin Eaborn In Memorium
DiEthicones maintain DiMethicones beneficial properties of excellent slip, spreading, gas permeab... more DiEthicones maintain DiMethicones beneficial properties of excellent slip, spreading, gas permeability, and water proofness due to similar physical properties, yet DiEthicone possess greater compatibility with common suncare and cosmetic ingredients.
Material Research Society Abstracts Fall 1997, 1997
Low temperature growth of gallium nitride on silicon via vapor phase epitaxy was investigated. Th... more Low temperature growth of gallium nitride on silicon via vapor phase epitaxy was investigated. The use of different nitrogen and gallium sources was explored. The gallium nitride deposition process was optimized by varying surface preparation, seed and buffer layer growth, and annealing conditions. Films were extensively characterized via X-ray diffraction, Rutherford backscatter, atomic force microscopy, X-ray photoemission spectroscopy, and Auger electron spectroscopy. Optimized growth rates of 60-120 A/min were achieved at 0.8 torr pressure, with 1:1 gallium to nitride ratio to within 0.1%. Films were hexagonal and polycrystalline with 3 nitride bi-layer buffers, with annealing, allowed stoichiometric gallium nitride growth of up to 6000 A, but the temperatures used were not high enough to deposit epitaxial gallium nitride.
Chemical Aspects of Electronic Ceramic Processing MRS Proceedings, 1998
This volume contains 65 papers from a symposium entitled "Chemical Aspects of Electronic Ceramics... more This volume contains 65 papers from a symposium entitled "Chemical Aspects of Electronic Ceramics Processing," held over four days at the 1997 MRS Fall Meeting in Boston. The common themes in all of the research presented in this volume are the creative use of chemistry principles for ceramic fabrication and a multidisciplinary approach to materials research. Inorganic chemistry, solid-state chemistry, chemical engineering, materials science and engineering, and electrical engineering have all been skillfully combined to produce materials which will play an increasingly more important part in our lives. As in prior years, chemical vapor deposition (CVD) continues to be a popular area of research and was the subject of approximately half of the papers in this volume. Particularly "hot" areas of research are new and improved precursors, delivery systems for low-vapor pressure precursors, and improved processing and materials properties. Papers are evenly divided between oxide ceramics and non- oxide ceramics.
Silicon Compounds: Silanes and Silicones A Survey of Properties and Chemistry 3rd edition (Japanese), 2013
An overview of silane and silicone chemistry in 15 full chapter reviews. A register of over 2500 ... more An overview of silane and silicone chemistry in 15 full chapter reviews. A register of over 2500 silicon compounds with physical properties, chemical structures and application data is provided. 608 pages + inserts. Review Chapters: An Organosilicon Chemistry Primer; Naming Silicon Compound; Polysilanes; Silicon-Based Anion Relay Chemistry; Bioactive Organosilanes;Cross-Couling of Silanols and Silanolates; Silicon-Based Blocking Agents; Silanes and Surfaces; Bond Dissociation Energies of Organosilicon Compounds; Si NMR: Practical Aspects; Infrared Analysis of Organosilicon Compounds; Ring-Opening Polymerization of Cyclosiloxanes; Telechelic Siloxane Oligomers; Silicones: Stable, Inert Media; Reactive Silicones and Elastomer Formulation. Detailed and referenced properties for ~2500 Silicon Compounds are presented. 608 pages
Metal-Organics for Materials, Polymers and Synthesis (4th edition), 2016
Metal-Organic Materials Science Articles and Registry of Compounds TOC: Crystallography; Lattices... more Metal-Organic Materials Science Articles and Registry of Compounds TOC: Crystallography; Lattices; Point Defects; Transition Metal Oxides; Metal Alkoxides and Diketonates; Some Synthetic Applications of Organoaluminum Compounds; Germanium Compounds: Chemistry and Applications; Industrial applications of Organotin Compounds; Catalytic Applications of Tin Compounds; Applications of Metal-Organic Titanium Compounds; Zirconium Compounds and Complexes in Organic Synthesis; Metal Trifluoromethanesulfonates; Sol-Gel Chemistry; Analytical Methods.
Silicon Compounds: Register and Review (1st edition), 1979
Silicon Chemistry Primer; S.S. Washburne Expedited Organic Synthesis; T.J. Barton Reactive Interm... more Silicon Chemistry Primer; S.S. Washburne Expedited Organic Synthesis; T.J. Barton Reactive Intermediates in Organosilicon Chemistry; P.F. Hudrlik Some Applications of Organosilicon Compounds; B. Arkles Techniques for Silylation
An overview of silane and silicone chemistry in 15 full chapter reviews. A register of over 2500 ... more An overview of silane and silicone chemistry in 15 full chapter reviews. A register of over 2500 silicon compounds with physical properties, chemical structures and application data is provided. 608 pages + inserts. Review Chapters: An Organosilicon Chemistry Primer; Naming Silicon Compound; Polysilanes; Silicon-Based Anion Relay Chemistry; Bioactive Organosilanes;Cross-Couling of Silanols and Silanolates; Silicon-Based Blocking Agents; Silanes and Surfaces; Bond Dissociation Energies of Organosilicon Compounds; Si NMR: Practical Aspects; Infrared Analysis of Organosilicon Compounds; Ring-Opening Polymerization of Cyclosiloxanes; Telechelic Siloxane Oligomers; Silicones: Stable, Inert Media; Reactive Silicones and Elastomer Formulation. Detailed and referenced properties for ~2500 Silicon Compounds are presented.
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Papers by Barry Arkles
This presentation explores four new such processes and protocols that match these requirements, namely:
• P-CVD SiNx: This process combines precursor thermal adsorption with the reaction with remote plasma ammonia. A demonstration is presented in which thermal adsorption of tri(isopropyl)cyclotrisilazane (TICZ) ensures a substrate driven nucleation and growth process that leads ultimately to conformal SiNx in extremely high aspect ratio structures. Concurrently, the application of a remote NH3 plasma eliminates any undesirable plasma-induced effects on the substrate and growing film.
• Single Pulse CVD/ALD: These are methods for pulsed deposition of thin films that offer significant reduction in the time to generate thin films by eliminating a number of the steps required in growth cycles. In the case of ALD, for instance, it reduces the number of steps required to grow every individual thin film layer from four to one, thus maximizing process efficiency and wafer throughput, and leading to competitive manufacturing cost of ownership and return on investment. The deposition of high quality cobalt films from cobalt tricarbonyl nitrosyl will be discussed in this context.
• Vapor Phase Transient Species Deposition. The discrete generation of transient species under conditions distinct from the substrate and the parent precursor will be discussed. This process enables the deposition of films in lower thermal or energetic substrate environments. It also enables the deposition of films at lower temperatures and ensures greater conformality of the deposited films, allowing film deposition on thermally or chemically fragile substrates.
• Integrated Synthesis and Deposition (ISD): A manufacturing paradigm comprising a method and system for real-time, closed-loop synthesis, supply, and consumption of precursors in IC manufacturing processes. In its simplest form, the system consists of a precursor synthesis chamber being physically interfaced with a thin film processing chamber, with precursor being synthesized on demand and supplied in a controlled fashion into the thin film processing chamber where it is consumed in the manufacturing process. This allows practical methods to employ highly reactive chemistry that otherwise could lead to explosive or highly toxic releases.
J.E. Mark Some Interesting Things about the Polysiloxanes; R.G. Nuzzo Micro, Nano, Macro: silico, Silicones and Soft-Lithography Off Road on the Road Map; I. Yilgor, E. Yilgor New Generation of Silicone-Urea Elastomers; M. J. Sailor Smart Dust: Photonic Crystals Derived from Nanocrystalline Porous Silicon; T. D. Tilley Participation of Ligand Alpha-Substituents in Bond Activations and Catalytic Transformations Involving Silicon; L. Rosenberg Catalytic Si-H Activation in the Synthesis and Modification of Organosilanes; I. N. Jung Dehydrogenative Double Silylation of Acetylenes; J. L. Leighton Straines Silacycles: A Powerful Platform for Asymmetric Reaction Design; U, Wiesner Polymer Approaches to Silicn Based Nanostructured Hybrid Materials; E. Liskola Molecular Control of Interface Chemistry by Atomic Layer Deposition (ALD); C. Strohmann About the Stereochemistry of Lithiated Silanes; V.S.-Y. Lin Gatekeeping Effect: Synthesis of Multi-functionalized Mesoporous Silica Nanospheres; R, West The Radical Chemistry of Stable Silylenes; R. Walsh What we have Learnes About the Stabilities Of Silarane; A. Sekiguchi Stable Disilyne with a Silicon-Silicon Triple Bond; S. Rubisztajn New Condensation Process Leading to the Formation of Siloxane Bonds; A. Basindale, P. Lickiss Colin Eaborn In Memorium