CONCENTRATION CONTROL UNIT, GAS CONTROL SYSTEM, FILM DEPOSITION APPARATUS, CONCENTRATION CONTROL METHOD AND CONCENTRATION CONTROL UNIT PROGRAM

摘要

To provide a concentration control unit for intermittently leading material gas from an evaporation tank, capable of controlling the flow rate of carrier gas or dilution gas so as to suppress the overshoot of the concentration of the material gas right after the supply period of the material gas starts.SOLUTION: A concentration control unit comprises: a density calculation part 32 for calculating the concentration of material gas on the basis of an output signal from a concentration monitor 50; and a set flow rate calculation part 33 for calculating the initial setting flow rate of a flow rate control unit 40 in the initial interval used as a period from the start in a second supply period after a first supply period to a second predetermined time on the basis of an actual concentration calculated by the density calculation part 32 at a first predetermined time in the first supply period when the material gas is supplied, an actual flow rate outputted from the flow rate control unit 40 at the first predetermined time in the first supply period, the set flow rate of the flow rate control unit 40 at the first predetermined time in the first supply period and a preset target concentration.SELECTED DRAWING: Figure 4