A highly reliable semiconductor device includes a first insulator, a second insulator, a first conductor, a third insulator, an oxide semiconductor, second and third conductors, a fourth insulator, a fourth conductor overlapping with a region between the second and third conductors, a fifth insulator, and a sixth insulator in this order. The fourth insulator is in contact with top and side surfaces of the oxide semiconductor, and a top surface of the third insulator. The fifth insulator is in contact with the side surface of the oxide semiconductor and the top surface of the third insulator so as to cover the oxide semiconductor, the second to fourth conductors, and the fourth insulator. The first, second, fifth, and sixth insulators have low permeability for hydrogen, water, and oxygen. The first and sixth insulators have a thinner thickness than the second and sixth insulators, respectively.

A highly reliable semiconductor device includes a first insulator, a second insulator, a first conductor, a third insulator, an oxide semiconductor, second and third conductors, a fourth insulator, a fourth conductor overlapping with a region between the second and third conductors, a fifth insulator, and a sixth insulator in this order. The fourth insulator is in contact with top and side surfaces of the oxide semiconductor, and a top surface of the third insulator. The fifth insulator is in contact with the side surface of the oxide semiconductor and the top surface of the third insulator so as to cover the oxide semiconductor, the second to fourth conductors, and the fourth insulator. The first, second, fifth, and sixth insulators have low permeability for hydrogen, water, and oxygen. The first and sixth insulators have a thinner thickness than the second and sixth insulators, respectively.

An anode material includes a silicon composite substrate. In the X-ray diffraction pattern of the anode material, the highest intensity at 2θ within the range of 28.0° to 29.0° is I.sub.2, and the highest intensity at 2θ within the range of 20.5° to 21.5° is I.sub.1, wherein 0<I.sub.2/I.sub.1≤1. The anode material has good cycle performance, and the battery prepared with the anode material has better rate performance and a lower swelling rate.

An anode material includes a silicon composite substrate. In the X-ray diffraction pattern of the anode material, the highest intensity at 2θ within the range of 28.0° to 29.0° is I.sub.2, and the highest intensity at 2θ within the range of 20.5° to 21.5° is I.sub.1, wherein 0<I.sub.2/I.sub.1≤1. The anode material has good cycle performance, and the battery prepared with the anode material has better rate performance and a lower swelling rate.

A process for fabricating an optical device includes injecting (301) optical silicone into a mold cavity formed by two or more mutually matching mold-elements, curing (302) the optical silicone contained by the mold cavity, and separating (303) the mold-elements from the optical device constituted by the optical silicone. The reversible elasticity of the optical silicone after the curing phase is utilized in the process so that at least one of the mold-elements has counterdraft which causes a reversible deformation in the optical device when the mold-element is separated from the optical device. As the counterdraft is allowable, the shape of the optical device as well as the dividing joints between the mold-elements can be designed more freely. For example, walls of the mold cavity corresponding to optically active surfaces of the optical device can be arranged to be free from dividing joints between the mold-elements.

Provided is a method of manufacturing silicon oxide by which an amount of oxygen of the silicon oxide may be controlled. The method of manufacturing silicon oxide may include mixing silicon and silicon dioxide to be included in a reaction chamber, depressurizing a pressure of the reaction chamber to obtain a high degree of vacuum while increasing a temperature in the reaction chamber to a reaction temperature, and reacting the mixture of silicon and silicon dioxide in a reducing atmosphere.

Provided is a method of manufacturing silicon oxide by which an amount of oxygen of the silicon oxide may be controlled. The method of manufacturing silicon oxide may include mixing silicon and silicon dioxide to be included in a reaction chamber, depressurizing a pressure of the reaction chamber to obtain a high degree of vacuum while increasing a temperature in the reaction chamber to a reaction temperature, and reacting the mixture of silicon and silicon dioxide in a reducing atmosphere.

Novel nanoparticle-coated multilayer shell microstructures are disclosed herein. Some variations of the invention provide a material comprising a plurality of hollow microstructures characterized by an average shortest diameter from about 5 microns to about 1 millimeter, wherein each of the microstructures comprises multiple shells, including at least an inner shell and an outmost shell, with a combined thickness that is less than one-tenth of the average shortest diameter. The inner shell and the outmost shell have different composition. The outmost shell comprises nanoparticles sized between about 10 nanometers to about 500 nanometers, and the nanoparticles each contain an oxide and/or are surrounded by an oxide layer having a layer thickness of at least 1 nanometer. Several microstructure configurations are illustrated in the drawings.

A method of preparing a silicon oxide (Si.sub.x)-carbon composite for a negative-electrode active material of a lithium secondary battery, includes mixing silicon (Si) particles and a polymer material with an organic solvent, thus preparing a mixture solution, optionally electrospinning the mixture solution thus preparing a composite having a one-dimensional structure, and heat-treating the mixture solution or the composite having a one-dimensional structure. The silicon oxide (SiO.sub.x)-carbon composite can reduce volume expansion upon lithium ion insertion and can increase ionic conductivity and electronic conductivity and thus can maintain high capacity, making it possible to apply it to a lithium ion battery to thus improve electrochemical characteristics of the battery.

A method of preparing a silicon oxide (Si.sub.x)-carbon composite for a negative-electrode active material of a lithium secondary battery, includes mixing silicon (Si) particles and a polymer material with an organic solvent, thus preparing a mixture solution, optionally electrospinning the mixture solution thus preparing a composite having a one-dimensional structure, and heat-treating the mixture solution or the composite having a one-dimensional structure. The silicon oxide (SiO.sub.x)-carbon composite can reduce volume expansion upon lithium ion insertion and can increase ionic conductivity and electronic conductivity and thus can maintain high capacity, making it possible to apply it to a lithium ion battery to thus improve electrochemical characteristics of the battery.