The invention relates to a plasma chemical vapor deposition (PCVD) apparatus for deposition of one or more layers of silica onto an interior wall of an elongated hollow glass substrate tube. The apparatus comprises a microwave generator, a plasma generator receiving microwaves from said generator in use, a cylindrical cavity extending through said generator, and a cylindrical liner positioned in the cavity. The substrate tube passes through the liner in use. The cylindrical liner has at least one section having a reduced inner diameter over a part of the length of the liner, the at least one section providing a contact zone for the substrate tube. The microwave generator is configured to generate microwaves having a wavelength Lw in the range of 40 to 400 millimeters, wherein a length of said at least one section having the reduced inner diameter is at most 0.1×Lw.

A high-frequency power circuit includes a first antenna circuit and a second antenna circuit that are connected in parallel to a matching box connected to a high-frequency power supply. The first antenna circuit include a first antenna, a first distribution capacitor, and a first variable capacitor. The second antenna circuit includes a second antenna, a second distribution capacitor, and a second variable capacitor. A controller sets a capacitance of the first variable capacitor based on a detection result of a phase difference between current and voltage in a series-connected portion of the first antenna and the first variable capacitor during plasma production to reduce this phase difference and sets a capacitance of the second variable capacitor based on a detection result of a phase difference between current and voltage in a series-connected portion of the second antenna and the second variable capacitor during plasma production to reduce this phase difference.

A high-frequency power circuit includes a first antenna circuit and a second antenna circuit that are connected in parallel to a matching box connected to a high-frequency power supply. The first antenna circuit include a first antenna, a first distribution capacitor, and a first variable capacitor. The second antenna circuit includes a second antenna, a second distribution capacitor, and a second variable capacitor. A controller sets a capacitance of the first variable capacitor based on a detection result of a phase difference between current and voltage in a series-connected portion of the first antenna and the first variable capacitor during plasma production to reduce this phase difference and sets a capacitance of the second variable capacitor based on a detection result of a phase difference between current and voltage in a series-connected portion of the second antenna and the second variable capacitor during plasma production to reduce this phase difference.

Systems, devices, and methods are discussed relating to plasma sources using load current switch timing of zero volt switching resonant topology.

A plasma processing apparatus 100 is equipped with a shower head 16 and a placing table 2 facing each other. A first RF power supply 10a is configured to apply a RF power to any one of the shower head 16 or the placing table 2 without igniting plasma. A measuring device 204 is configured to measure a physical quantity of the RF power applied by the first RF power supply 10a. A process controller 91 is configured to acquire an inter-electrode distance by using the measured physical quantity of the RF power in a correlation function of the inter-electrode distance and the physical quantity of the RF power.

A plasma processing apparatus 100 is equipped with a shower head 16 and a placing table 2 facing each other. A first RF power supply 10a is configured to apply a RF power to any one of the shower head 16 or the placing table 2 without igniting plasma. A measuring device 204 is configured to measure a physical quantity of the RF power applied by the first RF power supply 10a. A process controller 91 is configured to acquire an inter-electrode distance by using the measured physical quantity of the RF power in a correlation function of the inter-electrode distance and the physical quantity of the RF power.

A plasma processing apparatus includes a processing chamber in which a sample is subjected to plasma processing, a first radio frequency power supply that supplies radio frequency power for generating plasma, a sample stage on which the sample is mounted, and a second radio frequency power supply that supplies radio frequency power to the sample stage, the plasma processing apparatus further includes a DC power supply that applies a DC voltage, that is changed according to a periodically repeated waveform, to the sample stage, and the waveform of one cycle has a period in which amplitude changes by a predetermined amount or more during a predetermined time. Accordingly, charged particles on a wafer surface are removed, a trench shape with high verticality can be obtained, and damage to a film that is not to be etched inside a trench can be reduced.

A plasma processing apparatus includes a processing chamber in which a sample is subjected to plasma processing, a first radio frequency power supply that supplies radio frequency power for generating plasma, a sample stage on which the sample is mounted, and a second radio frequency power supply that supplies radio frequency power to the sample stage, the plasma processing apparatus further includes a DC power supply that applies a DC voltage, that is changed according to a periodically repeated waveform, to the sample stage, and the waveform of one cycle has a period in which amplitude changes by a predetermined amount or more during a predetermined time. Accordingly, charged particles on a wafer surface are removed, a trench shape with high verticality can be obtained, and damage to a film that is not to be etched inside a trench can be reduced.

A plasma-generation system is provided that includes a variable-frequency microwave generator configured to generate microwave power and a plasma applicator configured to use the microwave power from the microwave generator to (i) ignite a process gas therein for initiating a plasma in a plasma ignition process and (ii) maintain the plasma in a steady state process. The system also includes a coarse tuner connected between the microwave generator and the plasma applicator. At least one physical parameter of the coarse tuner is adapted to be set to achieve coarse impedance matching between the microwave generator and the plasma generated during both the plasma ignition process and the steady state process. A load impedance of the plasma generated during the plasma ignition process and the steady state process is adapted to vary. The microwave generator is configured to tune an operating frequency at the set physical parameter of the coarse tuner.

At a time of a wafer processing by a plasma processing apparatus, in order to prevent first radio frequency power from being diverted into an output line of a second radio frequency power supply via plasma, the plasma processing apparatus includes: a processing chamber in which a sample is plasma-processed; a sample stage that includes a first electrode and a second electrode disposed outside the first electrode and on which the sample is placed; a first radio frequency power supply configured to supply first radio frequency power to the first electrode via a first matching device and a first transmission path; and a second radio frequency power supply configured to supply second radio frequency power to the second electrode via a second matching device and a second transmission path. The plasma processing apparatus further includes a control device configured to control the first radio frequency power supply to supply the first radio frequency power to the sample stage when a preset value of the second matching device is a predetermined value. The predetermined value is a value that makes an impedance of the second transmission path an impedance at which the radio frequency power is not detected by the second matching device.