Patent ID: 7312584
Filing Date: 2007-12-25
Classification: C01B,G09G,H01J,H05B,H05H,Y02B

Abstract:
1. A plasma-generation power-supply device that drives a discharging load that generates a plasma, comprising: an alternating-current power-supply that supplies power to said discharging load; and a controller that is capable of controlling a frequency of an alternating output of said alternating-current power-supply, wherein said controller provides control to vary the power-supply frequency of said alternating-current power-supply in accordance with a target applied power to said discharging load, and said alternating-current power-supply is formed of an inverter, and said alternating output is a pulse output, and wherein when Cg: an electrostatic capacity value of a dielectric included in said discharging load, Ca: an electrostatic capacity value of a gas region included in said discharging load, Cp: a floating electrostatic capacity value in parallel with said discharging load, V*: a discharge maintaining voltage, L: an inductance value in a circuit including said discharging load, f: said power-supply frequency, and Cβ: an electrostatic capacity in a non-discharging state, then, said controller varies said power-supply frequency and a duty of said pulse output within a stable control region that is surrounded by: a characteristic curve of applied power that is obtained when said power-supply frequency is varied with said duty of said pulse output fixed at a maximum value; a curve representing 0.9 times a curve of an applied power Poz that is given by an expression below  and, a straight line representing a resonant frequency f