Substrate processing apparatus and electrode structure

A substrate processing apparatus comprising:

• a chamber that houses a substrate;
• a mounting stage that is arranged in the chamber, the substrate being mounted on the mounting stage, a first high-frequency power being supplied to the mounting stage;
• a disk-shaped shower head that is arranged such as to face the mounted substrate and that has a number of penetrating gas holes, a second high-frequency power being supplied to the shower head;
• a first pipe that is connected to the shower head and that supplies processing gas and additional gas to the shower head;
• a second pipe that is connected to the shower head and that supplies the processing gas and the additional gas to the shower head;
• a branch flow rate adjusting apparatus that adjusts a flow rate of the processing gas and the additional gas via the first pipe and that adjusts a flow rate of the processing gas and the additional gas via the second pipe;
• a first buffer vacancy that is comprised of a space formed in a center of the shower head;
• a second buffer vacancy that is comprised of an annular space formed at a peripheral portion of the shower head;
• and
• an annular partition wall member that separates the first buffer vacancy and the second buffer vacancy,
• wherein:
• the annular partition wall member separates a space inside the shower head with respect to a horizontal-radial direction of the shower head so as to form the first buffer vacancy and the second buffer vacancy;
• the first pipe is branched into at least two branched pipes, and the branched pipes are connected to the first buffer vacancy along a circumference of a circle arranged thereon at equal intervals;
• the second pipe is branched into at least two branched pipes, and the branched pipes are connected to the second buffer vacancy along a circumference of a circle arranged thereon at equal intervals;
• the branched pipes of the first pipe are connected to the first buffer vacancy via at least two first connecting sections, and the branched pipes of the second pipe are connected to the second buffer vacancy via at least two second connecting sections,
• the first connecting sections consisting of a first pair of inlets to the first buffer vacancy are arranged on the circumference of a circle on the first buffer vacancy at equal intervals,
• the second connecting sections consisting of a second pair of inlets to the second buffer vacancy are arranged on the circumference of a circle on the second buffer vacancy at equal intervals,
• when the total number of the first and second connecting sections is set to n, the first and second pairs are arranged respectively at rotational angle positions of 360°/n ±3° in a rotational system centering around the center of the shower head regardless of whether each of the first and second connecting sections is arranged on the circumference of the circle on the first buffer vacancy or the circumference of the circle on the second buffer vacancy, and
• the mixture of the processing gas and the additional gas is supplied symmetrically with respect to the center of the shower head and uniformly into the chamber so as to make uniform the distribution of an electric field generated in a processing space inside the chamber.