Plasma processing apparatus
A plasma processing apparatus includes a processing chamber, a first electrode and a second electrode disposed to face each other, a high frequency power supply unit for applying a high frequency power to either the first electrode or the second electrode, a processing gas supply unit for supplying a processing gas to a processing space, and a main dielectric member provided at a substrate mounting portion on a main surface of the first electrode. A focus ring is attached to the first electrode to cover a peripheral portion of the main surface of the first electrode and a peripheral dielectric member is provided in a peripheral portion on the main surface of the first electrode so that an electrostatic capacitance per unit area applied between the first electrode and the focus ring is smaller than that applied between the first electrode and the substrate by the main dielectric member.
1. A plasma processing apparatus comprising:
an evacuable processing chamber;
a main lower electrode to support a target substrate in the processing chamber;
a peripheral lower electrode extending in a ring shape to surround an outer periphery of the main lower electrode, the peripheral lower electrode being electrically insulated from the main lower electrode;
a focus ring attached to cover a top surface of the peripheral lower electrode;
an upper electrode disposed above the main lower electrode and the peripheral lower electrode to face thereto;
a processing gas supply unit to supply a processing gas to a processing space formed between the main lower electrode and the upper electrode;
a first high frequency power supply unit connected to the main lower electrode and the peripheral lower electrode via a matching unit to apply a first high frequency power having a first frequency;
a second high frequency power supply unit connected to the main lower electrode and the peripheral lower electrode via the matching unit to apply a second high frequency power having a second frequency lower than the first frequency; and
a filter, connected between the second high frequency power supply unit and the peripheral lower electrode, to pass the first high frequency power while blocking the second high frequency power.
2. The plasma processing apparatus of claim 1 , further comprising a main dielectric member provided on the top surface of the main lower electrode and a peripheral dielectric member provided on the top surface of the peripheral lower electrode,
wherein a thickness of the peripheral dielectric member is greater than a thickness of the main dielectric member.
3. The plasma processing apparatus of claim 2 , wherein a conductor is provided in the main dielectric member, and a DC voltage for generating an electrostatic attraction force to the substrate is applied to the conductor.
4. The plasma processing apparatus of claim 2 , wherein a conductor is provided in the peripheral dielectric member, and a DC voltage for generating an electrostatic attraction force to the focus ring is applied to the conductor.
5. The plasma processing apparatus of claim 1 , further comprising a main dielectric member provided on the top surface of the main lower electrode and a peripheral dielectric member provided on the top surface of the peripheral lower electrode,
wherein a thickness of the peripheral dielectric member is greater than a thickness of the main dielectric member,
wherein a conductor is provided in the peripheral dielectric member, and a DC voltage for generating an electrostatic attraction force to the focus ring is applied to the conductor.