The invention provides a process for preparing molybdenum and tungsten oxyhalide compounds which are useful in the deposition of molybdenum and tungsten containing films on various surfaces of microelectronic devices. In the process of the invention, a molybdenum or tungsten trioxide is heated in either a solid state medium or in a melt-phase reaction comprising a eutectic blend comprising alkaline and/or alkaline earth metal salts. The molybdenum or tungsten oxyhalides thus formed may be isolated as a vapor and crystallized to provide highly pure precursor compounds such as MoO.sub.2Cl.sub.2.

The invention provides a process for preparing molybdenum and tungsten oxyhalide compounds which are useful in the deposition of molybdenum and tungsten containing films on various surfaces of microelectronic devices. In the process of the invention, a molybdenum or tungsten trioxide is heated in either a solid state medium or in a melt-phase reaction comprising a eutectic blend comprising alkaline and/or alkaline earth metal salts. The molybdenum or tungsten oxyhalides thus formed may be isolated as a vapor and crystallized to provide highly pure precursor compounds such as MoO.sub.2Cl.sub.2.

The purpose of the present invention is to safely synthesize high purity tungsten pentachloride at a higher yield and at a higher purity than in prior art. This method for producing tungsten pentachloride includes: a step of mixing a reducing agent selected from the group consisting of Bi, Hg, Sb, Ti, Al, P, and As with tungsten hexachloride uniformly in an inert atmosphere with a molar ratio of the tungsten hexachloride to the reducing agent being 2.8:1.0 to 3.2:1.0 to obtain a mixture; a step of heating the mixture of the reducing agent and the tungsten hexachloride to 80 to 210 C. at 13 Pa or lower and reducing the same; a step of heating the reduced product of the mixture of the reducing agent and the tungsten hexachloride to 120 to 290 C. at 66 Pa or lower and vacuum distilling the same to remove impurities; and a step of heating the reduced product from which impurities have been removed by the vacuum distillation to 140 to 350 C. at 13 Pa or lower and purifying the same by sublimation to obtain the tungsten pentachloride.

The purpose of the present invention is to safely synthesize high purity tungsten pentachloride at a higher yield and at a higher purity than in prior art. This method for producing tungsten pentachloride includes: a step of mixing a reducing agent selected from the group consisting of Bi, Hg, Sb, Ti, Al, P, and As with tungsten hexachloride uniformly in an inert atmosphere with a molar ratio of the tungsten hexachloride to the reducing agent being 2.8:1.0 to 3.2:1.0 to obtain a mixture; a step of heating the mixture of the reducing agent and the tungsten hexachloride to 80 to 210 C. at 13 Pa or lower and reducing the same; a step of heating the reduced product of the mixture of the reducing agent and the tungsten hexachloride to 120 to 290 C. at 66 Pa or lower and vacuum distilling the same to remove impurities; and a step of heating the reduced product from which impurities have been removed by the vacuum distillation to 140 to 350 C. at 13 Pa or lower and purifying the same by sublimation to obtain the tungsten pentachloride.

Synthesis of tungsten pentahalide compositions having low impurity profiles are disclosed. The specific impurity profile permits deposition of high purity tungsten-containing films using vapor deposition processes or other semiconductor manufacturing processes without introduction of performance-impacting contaminants.

Synthesis of tungsten pentahalide compositions having low impurity profiles are disclosed. The specific impurity profile permits deposition of high purity tungsten-containing films using vapor deposition processes or other semiconductor manufacturing processes without introduction of performance-impacting contaminants.

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.

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.

According to the present invention, there is provided a method of producing tungsten hexafluoride by reacting tungsten with a fluorine-containing gas at a temperature of 800 C. or higher. The method according to the present invention is advantageous in that the amount of production of the tungsten hexafluoride per unit capacity of the reaction vessel is increased as compared to conventional techniques of producing tungsten hexafluoride from a fluorine-containing gas and metal tungsten while controlling the reaction temperature to 400 C. or lower. It is preferable that the reaction vessel is equipped with a coolant jacket for maintaining an inner wall temperature of the reaction vessel at 400 C. or lower.

According to the present invention, there is provided a method of producing tungsten hexafluoride by reacting tungsten with a fluorine-containing gas at a temperature of 800 C. or higher. The method according to the present invention is advantageous in that the amount of production of the tungsten hexafluoride per unit capacity of the reaction vessel is increased as compared to conventional techniques of producing tungsten hexafluoride from a fluorine-containing gas and metal tungsten while controlling the reaction temperature to 400 C. or lower. It is preferable that the reaction vessel is equipped with a coolant jacket for maintaining an inner wall temperature of the reaction vessel at 400 C. or lower.