Deposition methods may prevent or reduce crystallization of silicon in a deposited amorphous silicon film that may occur after annealing at high temperatures. The crystallization of silicon may be prevented by doping the silicon with an element. The element may be boron, carbon, or phosphorous. Doping above a certain concentration for the element prevents substantial crystallization at high temperatures and for durations at or greater than 30 minutes. Methods and devices are described.

A method for removing boron is provided, which includes (a) mixing a carbon source material and a silicon source material in a chamber to form a solid state mixture, (b) heating the solid state mixture to a temperature of 1000 C. to 1600 C., and adjusting the pressure of the chamber to 1 torr to 100 torr. The method also includes (c) conducting a gas mixture of a first carrier gas and water vapor into the chamber to remove boron from the solid state mixture, and (d) conducting a second carrier gas into the chamber.

A method for manufacturing an alloy formed from a boride of a precious metal, the method involving reacting a source of the precious metal with a source of boron in a salt or a mixture of salts in the molten state. The present invention also relates to an alloy formed from a boride of a precious metal, the alloy including crystalline nanoparticles of M.sub.xB.sub.y with M which is a precious metal, distributed in an amorphous matrix of B or in an amorphous matrix of B and of M.sub.zB.sub.a.

An object of the present invention is to provide a flow type reaction device which is capable of maintaining reaction efficiency and productivity which are sufficient for practical use for a long time, and reducing the size and cost of the reaction device, and the present invention provides a flow type reaction device (1) for continuously reacting two or more kinds of raw materials, including a mixing section (10) which is configured to mix two or more kinds of the raw materials, and a reaction section (20) which is provided on a secondary side with respect to the mixing section (10), and configured to obtain a product by reacting two or more kinds of the raw materials, the mixing section (10) includes a mixing device (13) which is configured to mix two or more kinds of the raw materials, and two or more supply pipes (L11, L12) which are configured to supply each of two or more kinds of the raw materials to the mixing device (13), the supply pipes (L11, L12) are respectively connected to the mixing device (13), and at least one of the supply pipes (L11) has, in the vicinity of a connection portion of the supply pipe (L11) with the mixing device (13), a suppression mechanism which is configured to suppress movement of a fluid from the mixing device (13) to the supply pipe (L11).

An object of the present invention is to provide a flow type reaction device which is capable of maintaining reaction efficiency and productivity which are sufficient for practical use for a long time, and reducing the size and cost of the reaction device, and the present invention provides a flow type reaction device (1) for continuously reacting two or more kinds of raw materials, including a mixing section (10) which is configured to mix two or more kinds of the raw materials, and a reaction section (20) which is provided on a secondary side with respect to the mixing section (10), and configured to obtain a product by reacting two or more kinds of the raw materials, the mixing section (10) includes a mixing device (13) which is configured to mix two or more kinds of the raw materials, and two or more supply pipes (L11, L12) which are configured to supply each of two or more kinds of the raw materials to the mixing device (13), the supply pipes (L11, L12) are respectively connected to the mixing device (13), and at least one of the supply pipes (L11) has, in the vicinity of a connection portion of the supply pipe (L11) with the mixing device (13), a suppression mechanism which is configured to suppress movement of a fluid from the mixing device (13) to the supply pipe (L11).

A method of preparing an atomically-dimensioned elemental boron allotrope includes providing a substrate at a temperature greater than about 200 C.; generating elemental boron vapor from a solid elemental boron source; and contacting said substrate with said boron vapor for at least one of a rate and at a pressure sufficient to deposit on said substrate a boron allotrope comprising an elemental boron layer comprising a boron atomic thickness dimension, said method under negative pressure.

A method of preparing an atomically-dimensioned elemental boron allotrope includes providing a substrate at a temperature greater than about 200 C.; generating elemental boron vapor from a solid elemental boron source; and contacting said substrate with said boron vapor for at least one of a rate and at a pressure sufficient to deposit on said substrate a boron allotrope comprising an elemental boron layer comprising a boron atomic thickness dimension, said method under negative pressure.

A boron structure body includes boron having each concentration of Ti, Al, Fe, Cr, Ni, Co, Cu, W, Ta, Mo and Nb being 0.1 ppmw or less and having a thickness of 0.8 to 5 mm. The boron structure body may have a tubular shape, and when used as a doping agent, a ratio of .sup.11B that is an isotope may be 95 mass % or more. The boron structure body can be easily crushed, and a high-purity boron powder having an average particle diameter of 0.5 to 3 mm and having each metal impurity concentration of 0.3 ppmw or less can be obtained.

Embodiments of the invention provide a method for atomic layer etching (ALE) of a substrate. According to one embodiment, the method includes providing a substrate, and exposing the substrate to hydrogen fluoride (HF) gas and a boron-containing gas to etch the substrate. According to another embodiment, the method includes providing a substrate containing a metal oxide film, exposing the substrate to HF gas to form a fluorinated surface layer on the metal oxide film, and exposing the substrate to a boron-containing gas to remove the fluorinated surface layer from the metal oxide film. The exposures may be repeated at least once to further etch the metal oxide film.

A method of preparing an atomically-dimensioned elemental boron allotrope includes providing a substrate at a temperature greater than about 200 C.; generating elemental boron vapor from a solid elemental boron source; and contacting said substrate with said boron vapor for at least one of a rate and at a pressure sufficient to deposit on said substrate a boron allotrope comprising an elemental boron layer comprising a boron atomic thickness dimension, said method under negative pressure.