Method for producing highly pure solutions using gaseous hydrogen fluoride
AssigneeHoneywell International Inc.
InventorsMichael A. Dodd, John McFarland, Wolfgang Sievert
Life of this patent
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Abstract
Methods for producing highly pure solutions containing hydrogen fluoride, one or more salts thereof or a mixture of two or more thereof, by adding hydrogen fluoride to at least one anhydrous solvent, wherein the hydrogen fluoride is added to the anhydrous solvent or solvents in the form of a gas or as a liquified gas or as a mixture of gas and liquefied gas. High purity hydrogen fluoride and ammonium fluoride solutions produced by the inventive method are also disclosed.
Claims17
A method for producing a highly pure solution consisting of hydrogen fluoride in at least one anhydrous solvent, said method comprising:
- adding anhydrous hydrogen fluoride with a metal ion content less than 1 part per billion (ppb) per metal, into at least one anhydrous solvent, wherein each solvent has an impurity content less than 1 ppb;
- and
- homogenizing by recirculation the hydrogen fluoride and solvent;
- wherein said hydrogen fluoride is added by means of an injector into said solvent in the form of a gas, or as a liquefied gas, or as a mixture of a gas and a liquefied gas.
A method for producing a highly pure ammonium fluoride solution comprising:
- adding into at least one anhydrous solvent anhydrous gaseous ammonia with a metal ion content less than 1 part per billion (ppb) per metal and anhydrous hydrogen fluoride with a metal ion content less than 1 ppb per metal, wherein each solvent has a total impurity content less than 1 ppb, and said ammonia and said hydrogen fluoride are added in amounts effective to provide a solution with an ammonium fluoride concentration between about 0.1 and about 50 percent by weight;
- and
- homogenizing by recirculation said ammonium fluoride solution;
- wherein said hydrogen fluoride is added by means of an injector into said solvent in the form of a gas, or as a liquefied gas, or as a mixture of a gas and a liquefied gas.
A method for producing a highly pure acid etching solution comprising:
- adding into at least one anhydrous solvent, anhydrous gaseous hydrogen chloride or anhydrous gaseous hydrogen bromide or a mixture thereof each with a metal ion content of less than 1 part per billion (ppb) per metal and anhydrous hydrogen fluoride with a metal ion content less than 1 ppb per metal, wherein each solvent has a total impurity content less than 1 ppb, and said hydrogen fluoride and hydrogen chloride and/or hydrogen bromide are in amounts effective to provide a solution with a stoichiometric ratio of hydrogen fluoride to hydrogen bromide and/or hydrogen chloride less than or equal to one;
- and
- homogenizing by recirculation said solution;
- wherein said hydrogen fluoride is added by means of an injector into said solvent in the form of a gas, or as a liquefied gas, or as a mixture of a gas and a liquefied gas.
Dependencies are inferred from the claim text.