A device which can be exposed to chemical vapors, such as a molybdenum vapor, a tungsten vapor, or any combination thereof, which has a coating covering at least a portion thereof. The coating reduces or inhibits mass change at an outer surface of the device from exposure to the vapor. In certain situations, the mass change is a mass gain, and the coating reduces or inhibits the mass gain of equal to or less than 1×10.sup.−5 g mm.sup.−2.

A device which can be exposed to chemical vapors, such as a molybdenum vapor, a tungsten vapor, or any combination thereof, which has a coating covering at least a portion thereof. The coating reduces or inhibits mass change at an outer surface of the device from exposure to the vapor. In certain situations, the mass change is a mass gain, and the coating reduces or inhibits the mass gain of equal to or less than 1×10.sup.−5 g mm.sup.−2.

A preprocessing method comprises a sintering step of heating a solid material container filled with a solid material using a temperature which is lower than either the melting point or sublimation of the solid material, whichever is lower, and crystallizing at least part of the solid material, and an impurity removal step of heating the solid material container filled with the solid material using a temperature which is lower than either the melting point or sublimation of the solid material, whichever is lower, and removing at least part of the impurities included in the solid material.

A preprocessing method comprises a sintering step of heating a solid material container filled with a solid material using a temperature which is lower than either the melting point or sublimation of the solid material, whichever is lower, and crystallizing at least part of the solid material, and an impurity removal step of heating the solid material container filled with the solid material using a temperature which is lower than either the melting point or sublimation of the solid material, whichever is lower, and removing at least part of the impurities included in the solid material.

The invention relates to a method for producing a compound of formula MX.sub.n from a precursor compound of formula MX.sub.m, where M is a metal, X is a halide selected from F, Cl, Br, J, m is a number selected from the range 2 to 8, and n is a number selected from the range 1 to 7, with the condition that n<m, comprising a method step in which the precursor compound is reduced with a silane compound to the compound of formula MX.sub.n.

The invention relates to a method for producing a compound of formula MX.sub.n from a precursor compound of formula MX.sub.m, where M is a metal, X is a halide selected from F, Cl, Br, J, m is a number selected from the range 2 to 8, and n is a number selected from the range 1 to 7, with the condition that n<m, comprising a method step in which the precursor compound is reduced with a silane compound to the compound of formula MX.sub.n.

Aspects disclosed herein include a system for generating singlet oxygen in a gas, the system comprising: a substrate; and hexanuclear clusters operably immobilized on at least a portion of the substrate; wherein each hexanuclear cluster comprises a photosensitive octahedral core complex characterized by formula FX1a: M.sub.6X.sub.8 (FX1a); wherein each M is independently Mo, W, or Re; wherein each X is independently a halide anion ligand; wherein the clusters are exposed to the gas and the gas comprises O.sub.2 gas; wherein the clusters are exposed to a light; and wherein each hexanuclear cluster is a photosensitizer configured to generate the gaseous singlet oxygen when irradiated by the light in the presence of the O.sub.2 gas.

A production method of tungsten hexafluoride according to one embodiment of the present invention includes: a first step of bringing tungsten having an oxide film into contact with a fluorine gas or inert gas containing 50 vol ppm to 50 vol % of hydrogen fluoride in a reactor, thereby removing the oxide film from the tungsten; and a second step of bringing the tungsten from which the oxide film has been removed by the first step into contact with a fluorine-containing gas to form tungsten hexafluoride.

A production method of tungsten hexafluoride according to one embodiment of the present invention includes: a first step of bringing tungsten having an oxide film into contact with a fluorine gas or inert gas containing 50 vol ppm to 50 vol % of hydrogen fluoride in a reactor, thereby removing the oxide film from the tungsten; and a second step of bringing the tungsten from which the oxide film has been removed by the first step into contact with a fluorine-containing gas to form tungsten hexafluoride.

Conditioning of tungsten pentachloride to form specific crystalline phases is disclosed. The specific crystalline phases permit stable vapor pressures over extended periods of time during vapor deposition and etching processes.