US 9,072,159 B2 · High-frequency power supply device and ignition voltage selection method

Abstract

When RF power is supplied from an RF generator to a load via a power supply unit, (a) the internal impedance of the RF generator is made lower than the characteristic impedance of the power supply unit, and (b) the load-end voltage is increased by selecting the electrical length LE of the power supply unit, which connects between the RF generator and the load to supply RF power, so that the electrical length LE has a predetermined relation with the fundamental wavelength λ of the RF AC. More specifically, the electrical length LE of the power supply unit is selected in such a way that, when the load end, which is the input end of the load, is in an open state, the electrical length LE is (2n−1)·(λ/4)−k·λ≦LE≦(2n−1)·(λ/4)+k·λ (n is an integer, k is {π−2·cos−1(1/K)}/(4π)) with respect to the fundamental wavelength λ of the RF AC.

Claims10

Dependent claims

An RF power supplying device comprising:

an RF generator unit that converts a DC of a DC power supply to an RF AC through a switching operation;
and
a power supply unit connected between an output end of said RF generator unit and a load end, which is an input end of a load, to supply the RF AC to the load, wherein
an internal impedance of said RF generator unit is lower than a characteristic impedance of said power supply, and
an electrical length (LE) of said power supply unit when the load end is in an open state is a value selected as (2n−1)·(λ/4)−k·λ≦LE≦(2n−1)·(λ/4)+k·λ (n is an integer, k is a constant in a range of 0 to λ/4) with respect to a fundamental wavelength λ of the RF AC.

2 more elements

An ignition voltage selection method that causes a plasma load to generate a plasma discharge at a load end that is an input end of the plasma load, the ignition voltage selection method performed when an RF generator unit supplies an RF AC to the plasma load via a power supply unit, the ignition voltage selection method comprising the steps of:

converting, by said RF generator unit, a DC of a DC power supply to an RF AC through a switching operation to make an internal impedance of said RF generator unit lower than a characteristic impedance of said power supply unit;
when said plasma load is in a non-discharge state, setting an electrical length LE of said power supply unit when the load end of the plasma load is in an open state to (2n−1)·(λ/4)−k·λ≦LE≦(2n−1)·(λ/4)+k·λ (n is an integer, k is a constant in a range of 0 to λ/4) with respect to a fundamental wavelength λ of the RF AC;
and
selecting a voltage of the load end of said plasma load, determined by the electrical length LE, as an ignition voltage.

1 more element

Dependencies are inferred from the claim text.

High-frequency power supply device and ignition voltage selection method

Life of this patent

High-frequency power supply device and ignition voltage selection method

Life of this patent

Abstract

Claims10