Abstract: An integrated system for producing high purity silicon dioxide comprising: a) a source of an oxygen-containing feed gas containing at least one impurity, b) an oxygen transport membrane cell containing an oxygen-selective transport membrane that has a cathode side and an opposing anode side, the membrane being at an elevated temperature effective for separation of oxygen in the feed gas from the impurity by transporting oxygen ions from the oxygen-containing feed gas through the membrane to the anode to form a purified oxygen permeate on the anodeside, while retaining an essentially oxygen-depleted, impurity-containing retentate on the cathode side, c) a passageway from the source (a) to the cathode side of the membrane cell, d) a silicon source, and e) a silicon oxidation furnace, in communication with the anode side of the membrane cell, for reaction of the purified oxygen permeate with silicon from the silicon source, at an elevated reaction temperature effective for the reaction, in order to produce the h

Abstract: The invention is a method of removing materials such as carbon and metallic elements from a substrate surface via heating in an atmosphere of molecular chlorine and steam. In a preferred embodiment, carbon residue is removed from the surface of a Si or GaAs substrate material.

Abstract: The invention is a method of removing materials such as carbon and metallic elements from a substrate surface via heating in an atmosphere of molecular chlorine and steam. In a preferred embodiment, carbon residue is removed from the surface of a Si or GaAs substrate material.