Patent ID: 8151814

Claim:
A method for controlling flow and concentration of a liquid precursor, comprising: supplying a carrier gas to a first auto-pressure regulator and outputting therefrom the carrier gas at a first pressure to an inlet of a precursor reservoir that stores a liquid and vaporized precursor, thereby outputting a mixture of the vaporized precursor and the carrier gas from the precursor reservoir through an outlet of the precursor reservoir, said first auto-pressure regulator being provided upstream of the precursor reservoir; and supplying the mixture of the vaporized precursor and the carrier gas to a second auto-pressure regulator and outputting therefrom the mixture at a second pressure to a reactor via an orifice, said second auto-pressure regulator being provided downstream of the precursor reservoir and said orifice being provided downstream of said second auto-pressure regulator, wherein the first and second auto-pressure regulators are each a regulator that maintains a set pressure using a built-in pressure sensor.