Alps Electric Co., Ltd.

Other

Tadashi Kumagai

Tadahiro Ohmi

Akira Nakano

Tomofumi Oba

Shoji Ogasawara

A plasma processing apparatus includes a radio frequency generator, a plasma processing chamber, a matching circuit for impedance matching between the radio frequency generator and the plasma processing chamber, and matching circuit adjusting means for matching the output impedance of the matching circuit to the impedance of the plasma processing chamber in a nondischarge state. The matching circuit is a product matching circuit that is produced based on a circuit constant of an adjusting matching circuit. The adjusting matching circuit is disposed between the radio frequency generator and the plasma processing chamber for a required plasma treatment and the circuit constant is determined by impedance matching between the radio frequency generator and the plasma processing chamber so that the adjusting matching circuit matches the load impedance of the plasma processing chamber.

Plasma processing apparatus, method for operating the same, designing system of matching circuit, and plasma processing method

A plasma processing apparatus of the present invention includes a matching circuit for impedance matching between a radio-frequency generator and a plasma processing chamber, and one or a plurality of impedance converting circuits provided between the matching circuit and the radio-frequency generator. The impedance converting circuit converts an impedance to decrease a difference in impedance to be matched by the matching circuit, thereby decreasing a change in the output impedance with a moving amount of a capacitance control of one of variable passive elements of the matching circuit, such as a load capacitor and a tuning capacitor. Therefore, a change in the impedance of the plasma processing chamber can be finely controlled.

Plasma processing apparatus

A first phase locked loop produces a local oscillator signal. The output of a second phase locked loop is connected to the input of the first phase locked loop. A first variable frequency divider is connected in the first phase locked loop. A second variable frequency divider having the same frequency division ratio as the first frequency divider is connected between a variable frequency oscillator and the input of the second phase locked loop. An adder adds a base frequency of preferably 1 MHz to the output frequency of the second frequency divider. With the frequency of the variable frequency oscillator set at a center frequency, the frequency of the local oscillator signal is equal to the frequency division ratio of the frequency dividers multiplied by 1 MHz. Any variation in the frequency of the variable frequency oscillator from the center frequency is algebraically added to the local oscillator frequency, regardless of the frequency division ratio, as an offset frequency. The frequency range of the variable frequency oscillator is low compared to the frequency range of the local oscillator signal, thereby enabling low frequency drift. A gate disables the first phase locked loop when the second phase locked loop is not in lock.

Local oscillator circuit having two phase locked loops having respective

A VHF mixer serves as an amplifier-mixer for VHF and an IF amplifier for UHF and CATV. UHF and CATV tuners produce the UHF and CATV IF signals respectively. A band selector switch enables a VHF local oscillator and disables UHF and CATV local oscillators to receive VHF, enables the UHF local oscillator and disables the VHF and CATV local oscillators to receive UHF and enables the CATV local oscillator and disables the VHF and UHF local oscillators to receive CATV.

Growing community of inventors

Fukushima-ken, Japan

Tadashi Kumagai