Showing papers on "Silicon oxide published in 2015"

Intrinsic Electron Mobility Exceeding 103 cm2/(V s) in Multilayer InSe FETs

Abstract: Graphene-like two-dimensional (2D) materials not only are interesting for their exotic electronic structure and fundamental electronic transport or optical properties but also hold promises for device miniaturization down to atomic thickness. As one material belonging to this category, InSe, a III–VI semiconductor, not only is a promising candidate for optoelectronic devices but also has potential for ultrathin field effect transistor (FET) with high mobility transport. In this work, various substrates such as PMMA, bare silicon oxide, passivated silicon oxide, and silicon nitride were used to fabricate multilayer InSe FET devices. Through back gating and Hall measurement in four-probe configuration, the device’s field effect mobility and intrinsic Hall mobility were extracted at various temperatures to study the material’s intrinsic transport behavior and the effect of dielectric substrate. The sample’s field effect and Hall mobilities over the range of 20–300 K fall in the range of 0.1–2.0 × 103 cm2/(V ...

Physical and chemical mechanisms in oxide-based resistance random access memory.

Abstract: In this review, we provide an overview of our work in resistive switching mechanisms on oxide-based resistance random access memory (RRAM) devices. Based on the investigation of physical and chemical mechanisms, we focus on its materials, device structures, and treatment methods so as to provide an in-depth perspective of state-of-the-art oxide-based RRAM. The critical voltage and constant reaction energy properties were found, which can be used to prospectively modulate voltage and operation time to control RRAM device working performance and forecast material composition. The quantized switching phenomena in RRAM devices were demonstrated at ultra-cryogenic temperature (4K), which is attributed to the atomic-level reaction in metallic filament. In the aspect of chemical mechanisms, we use the Coulomb Faraday theorem to investigate the chemical reaction equations of RRAM for the first time. We can clearly observe that the first-order reaction series is the basis for chemical reaction during reset process in the study. Furthermore, the activation energy of chemical reactions can be extracted by changing temperature during the reset process, from which the oxygen ion reaction process can be found in the RRAM device. As for its materials, silicon oxide is compatible to semiconductor fabrication lines. It is especially promising for the silicon oxide-doped metal technology to be introduced into the industry. Based on that, double-ended graphene oxide-doped silicon oxide based via-structure RRAM with filament self-aligning formation, and self-current limiting operation ability is demonstrated. The outstanding device characteristics are attributed to the oxidation and reduction of graphene oxide flakes formed during the sputter process. Besides, we have also adopted a new concept of supercritical CO2 fluid treatment to efficiently reduce the operation current of RRAM devices for portable electronic applications.

Method for forming film having low resistance and shallow junction depth

Abstract: A method for forming on a substrate a doped silicon oxide film with a cap film, includes: forming an arsenosilicate glass (ASG) film as an arsenic (As)-doped silicon oxide film on a substrate; continuously treating a surface of the ASG film with a treating gas constituted by Si, N, and H without excitation; and continuously forming a silicon nitride (SiN) film as a cap film on the treated surface of the ASG film.

One-step synthesis of Si@C nanoparticles by laser pyrolysis: high-capacity anode material for lithium-ion batteries.

Abstract: Carbon-covered silicon nanoparticles (Si@C) were synthesized for the first time by a one-step continuous process in a novel two stages laser pyrolysis reactor. Crystallized silicon cores formed in a first stage were covered in the second stage by a continuous shell mainly consisting in low organized sp2 carbon. At the Si/C interface silicon carbide is absent. Moreover, the presence of silicon oxide is reduced compared to materials synthesized in several steps, allowing the use of such material as promising anode material in lithium-ion batteries (LIB). Auger Electron Spectroscopy (AES) analysis of the samples at both SiKLL and SiLVV edges proved the uniformity of the carbon coating. Cyclic voltammetry was used to compare the stability of Si and Si@C active materials. In half-cell configuration, Si@C exhibits a high and stable capacity of 2400 mAh g–1 at C/10 and up to 500 mAh g–1 over 500 cycles at 2C. The retention of the capacity is attributed to the protective effect of the carbon shell, which avoids d...

Structural changes and conductance thresholds in metal-free intrinsic SiOx resistive random access memory

Abstract: We present an investigation of structural changes in silicon-rich silicon oxide metal-insulator-metal resistive RAM devices. The observed unipolar switching, which is intrinsic to the bulk oxide material and does not involve movement of metal ions, correlates with changes in the structure of the oxide. We use atomic force microscopy, conductive atomic force microscopy, x-ray photoelectron spectroscopy, and secondary ion mass spectroscopy to examine the structural changes occurring as a result of switching. We confirm that protrusions formed at the surface of samples during switching are bubbles, which are likely to be related to the outdiffusion of oxygen. This supports existing models for valence-change based resistive switching in oxides. In addition, we describe parallel linear and nonlinear conduction pathways and suggest that the conductance quantum, G0, is a natural boundary between the high and low resistance states of our devices.

Etching method and plasma processing apparatus

Abstract: An etching method is provided. In the etching method, a silicon oxide film is etched by using plasma in a first condition. In the first condition, a surface temperature of a substrate is controlled to have a temperature lower than −35 degrees C., and the plasma is generated from a hydrogen-containing gas and a fluorine-containing gas by using first radio frequency power output from a first radio frequency power source and second radio frequency power output from a second radio frequency power source. Next, the silicon oxide film is etched by using the plasma in a second condition. In the second condition, the output of the second radio frequency power from the second radio frequency power source is stopped. The silicon oxide film is etched by using the plasma alternately in the first condition and in the second condition multiple times.

Self-aligned process

Abstract: Methods of forming self-aligned structures on patterned substrates are described. The methods may be used to form metal lines or vias without the use of a separate photolithography pattern definition operation. Self-aligned contacts may be produced regardless of the presence of spacer elements. The methods include directionally ion-implanting a gapfill portion of a gapfill silicon oxide layer to implant into the gapfill portion without substantially ion-implanting the remainder of the gapfill silicon oxide layer (the sidewalls). Subsequently, a remote plasma is formed using a fluorine-containing precursor to etch the patterned substrate such that the gapfill portions of silicon oxide are selectively etched relative to other exposed portions exposed parallel to the ion implantation direction. Without ion implantation, the etch operation would be isotropic owing to the remote nature of the plasma excitation during the etch process.

Bipolar resistive switching and charge transport in silicon oxide memristor

Abstract: Reproducible bipolar resistive switching has been studied in SiO x -based thin-film memristor structures deposited by magnetron sputtering technique on the TiN/Ti metalized SiO 2 /Si substrates. It is established that, after electroforming, the structure can be switched between the quasi-ohmic low-resistance state related to silicon chains (conducting filaments) and the high-resistance state with semiconductor-like hopping mechanism of charge transport through the defects in silicon oxide. The switching parameters are determined by a balance between the reduction and oxidation processes that, in turn, are driven by the value and polarity of voltage bias, current, temperature and device environment. The results can be used for the development of silicon-based nonvolatile memory and memristive systems as a key component of future electronics.

Isotropic atomic layer etch for silicon and germanium oxides

Abstract: Methods for controlled isotropic etching of layers of silicon oxide and germanium oxide with atomic scale fidelity are provided. The methods make use of a reaction of anhydrous HF with an activated surface of an oxide, with an emphasis on removal of water generated in the reaction. In certain embodiments the oxide surface is first modified by adsorbing an OH-containing species (e.g., an alcohol) or by forming OH bonds using a hydrogen-containing plasma. The activated oxide is then etched by a separately introduced anhydrous HF, while the water generated in the reaction is removed from the surface of the substrate as the reaction proceeds, or at any time during or after the reaction. These methods may be used in interconnect pre-clean applications, gate dielectric processing, manufacturing of memory devices, or any other applications where accurate removal of one or multiple atomic layers of material is desired.

Vertical gate separation

Abstract: Methods of selectively etching tungsten from the surface of a patterned substrate are described. The methods electrically separate vertically arranged tungsten slabs from one another as needed. The vertically arranged tungsten slabs may form the walls of a trench during manufacture of a vertical flash memory cell. The tungsten etch may selectively remove tungsten relative to films such as silicon, polysilicon, silicon oxide, aluminum oxide, titanium nitride and silicon nitride. The methods include exposing electrically-shorted tungsten slabs to remotely-excited fluorine formed in a remote plasma region. Process parameters are provided which result in uniform tungsten recess within the trench. A low electron temperature is maintained in the substrate processing region to achieve high etch selectivity and uniform removal throughout the trench.

Isotropic atomic layer etch for silicon oxides using no activation

Abstract: Methods for controlled isotropic etching of layers of silicon oxide and germanium oxide with atomic scale fidelity are provided. The methods make use of NO activation of an oxide surface. Once activated, a fluorine-containing gas or vapor etches the activated surface. Etching is self-limiting as once the activated surface is removed, etching stops since the fluorine species does not spontaneously react with the un-activated oxide surface. These methods may be used in interconnect pre-clean applications, gate dielectric processing, manufacturing of memory devices, or any other applications where accurate removal of one or multiple atomic layers of material is desired.

Ultrathin random copolymer-grafted layers for block copolymer self-assembly.

Abstract: Hydroxyl-terminated P(S-r-MMA) random copolymers (RCPs) with molecular weights (Mn) from 1700 to 69000 and a styrene unit fraction of approximately 61% were grafted onto a silicon oxide surface and...

Self-Assembly Formation of Lipid Bilayer Coatings on Bare Aluminum Oxide: Overcoming the Force of Interfacial Water

Abstract: Widely used in catalysis and biosensing applications, aluminum oxide has become popular for surface functionalization with biological macromolecules, including lipid bilayer coatings. However, it is difficult to form supported lipid bilayers on aluminum oxide, and current methods require covalent surface modification, which masks the interfacial properties of aluminum oxide, and/or complex fabrication techniques with specific conditions. Herein, we addressed this issue by identifying simple and robust strategies to form fluidic lipid bilayers on aluminum oxide. The fabrication of a single lipid bilayer coating was achieved by two methods, vesicle fusion under acidic conditions and solvent-assisted lipid bilayer (SALB) formation under near-physiological pH conditions. Importantly, quartz crystal microbalance with dissipation (QCM-D) monitoring measurements determined that the hydration layer of a supported lipid bilayer on aluminum oxide is appreciably thicker than that of a bilayer on silicon oxide. Fluor...

Cleaning high aspect ratio vias

Abstract: A method of removing an amorphous silicon/silicon oxide film stack from vias is described. The method may involve a remote plasma comprising fluorine and a local plasma comprising fluorine and a nitrogen-and-hydrogen-containing precursor unexcited in the remote plasma to remove the silicon oxide. The method may then involve a local plasma of inert species to potentially remove any thin carbon layer (leftover from the photoresist) and to treat the amorphous silicon layer in preparation for removal. The method may then involve removal of the treated amorphous silicon layer with several options possibly within the same substrate processing region. The bottom of the vias may then possess exposed single crystal silicon which is conducive to epitaxial single crystal silicon film growth. The methods presented herein may be particularly well suited for 3d NAND (e.g. VNAND) device formation.

Correction to “Quantitative Analysis of the Effect of Hydrogen Diffusion From Silicon Oxide Etch-Stopper Layer Into Amorphous In–Ga–Zn–O on Thin-Film Transistor”

Abstract: In the above paper [1] , co-author D. Wang’s name was incorrectly spelled in both the biography and the byline. The correct spelling is Dapeng Wang.

Solvent-assisted lipid self-assembly at hydrophilic surfaces: factors influencing the formation of supported membranes.

Abstract: As a simple and efficient technique, the solvent-assisted lipid bilayer (SALB) formation method offers a versatile approach to fabricating a planar lipid bilayer on solid supports. Corresponding mechanistic aspects and the role of various governing parameters remain, however, to be better understood. Herein, we first scrutinized the effect of lipid concentration (0.01 to 5 mg/mL) and solvent type (isopropanol, n-propanol, or ethanol) on SALB formation on silicon oxide in order to identify optimal conditions for this process. The obtained fluid-phase lipid layers on silicon oxide were investigated by using the quartz crystal microbalance with dissipation monitoring, epifluorescence microscopy, and atomic force microscopy. The experimental results indicate that, in alcohol, lipid attachment to the substrate is reversible and reaches equilibrium in accordance with the bulk lipid concentration. During the solvent-exchange step, the water fraction increases and the deposited lipids are converted into planar bi...

Atomic layer deposition of MoS2 thin films

Abstract: Atomic layer deposition (ALD) was used to grow thin films of MoS2 over 5 × 5 cm areas of silicon oxide coated silicon wafers. Smooth, uniform, and continuous films were produced over a temperature range of 350 °C–450 °C. The as-grown films were analyzed using x-ray photoelectron spectroscopy, Raman spectroscopy, photoluminescence, and x-ray diffraction. Electrical characteristics of the films were evaluated by fabricating a back gated field effect transistor. These analyses indicate that ALD technique can produce large area, high quality MoS2 films.

Quantification of Silane Molecules on Oxidized Silicon: Are there Options for a Traceable and Absolute Determination?

Abstract: Organosilanes are used routinely to functionalize various support materials for further modifications. Nevertheless, reliable quantitative information about surface functional group densities after layer formation is rarely available. Here, we present the analysis of thin organic nanolayers made from nitrogen containing silane molecules on naturally oxidized silicon wafers with reference-free total reflection X-ray fluorescence (TXRF) and X-ray photoelectron spectroscopy (XPS). An areic density of 2–4 silane molecules per nm2 was calculated from the layer’s nitrogen mass deposition per area unit obtained by reference-free TXRF. Complementary energy and angle-resolved XPS (ER/AR-XPS) in the Si 2p core-level region was used to analyze the outermost surface region of the organic (silane layer)–inorganic (silicon wafer) interface. Different coexisting silicon species as silicon, native silicon oxide, and silane were identified and quantified. As a result of the presented proof-of-concept, absolute and traceab...

Antifungal effect of magnesium oxide, zinc oxide, silicon oxide and copper oxide nanoparticles against candida albicans

Abstract: Results: The results showed that MIC of nano-MgO and nano SiO 2 was greater than 3200 µg/mL, but MIC and MFC of nano-ZnO was recorded 200 µg/mL and 400 µg/mL, respectively. The MIC and MFC of nano-CuO was 400 µg/mL. The MIC and MFC of amphotericin B was 0.5 µg/mL and 2 µg/mL, respectively. Conclusions: It is concluded that, ZnO and CuO nanoparticles have anti C. albicans properties and may be used in treatment of infections caused by this fungus that should be investigated in vivo.

Vitrification of Thin Polymer Films: From Linear Chain to Soft Colloid-like Behavior

Abstract: We show that the vitrification of star-shaped polystyrene (PS), of functionality f and molecular weight per arm Mwarm, thin films supported by silicon oxide, SiOx, is strongly dependent on Mwarm and f. When f is small, the vitrification behavior is similar to that of linear-chain PS where the average glass transition, Tg, decreases with decreasing film thickness (ΔTg 0. We show that the overall vitrification behavior of these thin film star-shaped polymers is due to compet...

Monolithic three-dimensional nand strings and methods of fabrication thereof

Abstract: A vertically repeating stack of a unit layer stack is formed over a substrate. The unit layer stack includes a sacrificial material layer, a lower silicon oxide material layer, a first silicon oxide material layer, and an upper silicon oxide material layer. A memory opening can be formed through the vertically repeating stack, and a layer stack including a blocking dielectric layer, a memory material layer, a tunneling dielectric, and a semiconductor channel can be formed in the memory opening. The sacrificial material layers are replaced with electrically conductive layers. The first silicon oxide material layer can be removed to form backside recesses. Optionally, portions of the memory material layer can be removed to from discrete charge storage regions. The backside recesses can be filled with a low-k dielectric material and/or can include cavities within a dielectric material to provide reduced coupling between electrically conductive layers.

Selectively etching metals and metal nitrides conformally

Abstract: Methods of selectively etching metals and metal nitrides from the surface of a substrate are described. The etch selectively removes metals and metal nitrides relative to silicon-containing layers such as silicon, polysilicon, silicon oxide, silicon germanium, silicon carbide, silicon carbon nitride and/or silicon nitride. The etch removes material in a conformal manner by including an oxidation operation which creates a thin uniform metal oxide. The thin uniform metal oxide is then removed by exposing the metal oxide to a metal-halogen precursor in a substrate processing region. The metal oxide may be removed to completion and the etch may stop once the uniform metal oxide layer is removed. Etches described herein may be used to uniformly trim back material on high aspect ratio features which ordinarily show higher etch rates near the opening of a gap compared to deep within the gap.

Compositions and methods using same for deposition of silicon-containing film

Abstract: Described herein are compositions and methods using same for forming a silicon-containing film or material such as without limitation a silicon oxide, silicon nitride, silicon oxynitride, a carbon-doped silicon nitride, or a carbon-doped silicon oxide film in a semiconductor deposition process, such as without limitation, a plasma enhanced atomic layer deposition of silicon-containing film.

Graphene-coated porous silicon-carbon composite and method of manufacturing the same

Abstract: Provided are a porous silicon-carbon composite, which includes a core including a plurality of active particles, a conductive material formed on at least a portion of surfaces of the active particles, first pores, and second pores, and a first shell layer which is coated on the core and includes graphene, wherein the active particles include a plurality of silicon particles, silicon oxide particles, or a combination thereof, the first pores are present in the core and are formed by agglomeration of the plurality of active particles, and the second pores are irregularly dispersed and present in the core, has an average particle diameter smaller than an average particle diameter of the active particles, and are spherical, a method of manufacturing the same, and a negative electrode and a lithium secondary battery including the porous silicon-carbon composite.

Scalable Preparation of Ternary Hierarchical Silicon Oxide–Nickel–Graphite Composites for Lithium‐Ion Batteries

Abstract: Silicon monoxide is a promising anode candidate because of its high theoretical capacity and good cycle performance. To solve the problems associated with this material, including large volume changes during charge-discharge processes, we report a ternary hierarchical silicon oxide-nickel-graphite composite prepared by a facile two-step ball-milling method. The composite consists of nano-Si dispersed silicon oxides embedded in nano-Ni/graphite matrices (Si@SiOx /Ni/graphite). In the composite, crystalline nano-Si particles are generated by the mechanochemical reduction of SiO by ball milling with Ni. These nano-Si dispersed oxides have abundant electrochemical activity and can provide high Li-ion storage capacity. Furthermore, the milled nano-Ni/graphite matrices stick well to active materials and interconnect to form a crosslinked framework, which functions as an electrical highway and a mechanical backbone so that all silicon oxide particles become electrochemically active. Owing to these advanced structural and electrochemical characteristics, the composite enhances the utilization efficiency of SiO, accommodates its large volume expansion upon cycling, and has good ionic and electronic conductivity. The composite electrodes thus exhibit substantial improvements in electrochemical performance. This ternary hierarchical Si@SiOx /Ni/graphite composite is a promising candidate anode material for high-energy lithium-ion batteries. Additionally, the mechanochemical ball-milling method is low cost and easy to reproduce, indicating potential for the commercial production of the composite materials.

Negative electrode active material for non-aqueous electrolyte cell, negative electrode for non-aqueous electrolyte secondary cell, non-aqueous electrolyte secondary cell, and cell pack

Abstract: [Problem] To provide a negative electrode active material for a non-aqueous electrolyte cell having high initial charge/discharge efficiency and exceptional cycle characteristics. [Solution] A negative electrode active material for a non-aqueous electrolyte secondary cell according to an embodiment has silicon or silicon oxide having silicon therein, a carbonaceous material enclosing the silicon or silicon oxide having silicon therein, and a phase containing a silicate compound and an electroconductive aid present between the carbonaceous material and the silicon or silicon oxide having silicon therein.

Fabrication method and structure of semiconductor non-volatile memory device

Abstract: A non-volatile semiconductor memory device with good write/erase characteristics is provided. A selection gate is formed on a p-type well of a semiconductor substrate via a gate insulator, and a memory gate is formed on the p-type well via a laminated film composed of a silicon oxide film, a silicon nitride film, and a silicon oxide film. The memory gate is adjacent to the selection gate via the laminated film. In the regions on both sides of the selection gate and the memory gate in the p-type well, n-type impurity diffusion layers serving as the source and drain are formed. The region controlled by the selection gate and the region controlled by the memory gate located in the channel region between said impurity diffusion layers have the different charge densities of the impurity from each other.

Semiconductor device and manufacturing method of the same

Abstract: PROBLEM TO BE SOLVED: To increase carrier life time.SOLUTION: A semiconductor device manufacturing method includes: a process of forming a semiconductor layer 12 containing barium silicide on a substrate 10; and a process of forming a barium layer or a silicon layer 14 on the semiconductor layer 12 without exposing a surface of the semiconductor layer 12 in an oxidation atmosphere. A semiconductor device comprises: a semiconductor layer 12 including a barium silicide formed on a substrate 10; and a surface layer 14 which is formed on the semiconductor layer 12, and has an atom ratio of barium against barium and silicon, which is larger than the atom ratio in the semiconductor layer and includes barium oxide (or has an atom ratio of silicon against barium and silicon, which is larger than the atom ratio in the semiconductor layer and includes silicon oxide).