Patent ID: 7926509

Claim:
A method for the flow rate control of a clustering fluid, wherein the clustering fluid is hydrogen fluoride gas, the method comprising the steps of: supplying hydrogen fluoride gas from a gas supply source to an instrument or apparatus using a pressure type flow rate control device; and heating the pressure type flow rate control device so that an association of molecules of the hydrogen fluoride gas passing through the pressure type flow rate control device is dissociated so the hydrogen fluoride gas, while kept in a monomolecular state, is supplied by the pressure type flow rate control device while subjected to flow rate control, wherein heat is applied to one or more of an upstream side of an orifice of the pressure type flow rate control device and an upstream side of a valve chamber of the pressure type flow rate control device, wherein the hydrogen fluoride gas is supplied to a chamber of the instrument or apparatus, wherein the chamber is low-pressurized to 10 −2 to 10 2 Torr to form a near-vacuum and flow rate control is precisely maintained with a flow rate error of less than 2.4 SCCM over the flow rate range of 3 to 300 SCCM.