Stage and plasma processing apparatus
A stage on which a substrate is disposed includes: a base embedded with an adsorption electrode therein; a focus ring provided above the adsorption electrode and adsorbed and held on the base; and a deposit control ring provided radially inside the focus ring on the base. A gap is formed between the focus ring and the deposit control ring in a radial direction to separate the focus ring and the deposit control ring.
1. A stage on which a substrate is disposed, comprising:
a base embedded with an adsorption electrode therein;
a focus ring provided above the adsorption electrode and adsorbed and held on the base; and
a deposit control ring provided radially inside the focus ring on the base,
wherein a gap is formed between the focus ring and the deposit control ring in a radial direction to separate the focus ring and the deposit control ring, and
at least a contact surface of the deposit control ring or a contact surface of the base is surface-treated such that a contact thermal resistance between the deposit control ring and the base becomes larger than a contact thermal resistance between the focus ring and the base.
2. The stage according to claim 1 , wherein the gap extends in a vertical direction.
3. The stage according to claim 1 , wherein an upper end portion is formed on an outer peripheral portion of the focus ring such that an upper surface side of the focus ring projects radially inward,
a lower end portion is formed on an outer peripheral portion of the deposit control ring such that a lower surface side of the deposit control ring projects radially outward, and
the gap has a labyrinth structure formed by the upper end portion and the lower end portion.
4. The stage according to claim 2 , wherein an inner diameter of the upper surface of the focus ring is larger than an outer diameter of the substrate disposed on the base, and
an interval between an inner peripheral surface on the upper surface side of the focus ring and an outer peripheral surface of the substrate is larger than 0 mm and equal to or less than 1 mm.
5. The stage according to claim 1 , wherein a lower end portion is formed on an outer peripheral portion of the focus ring such that a lower surface side of the focus ring projects radially inward,
an upper end portion is formed on an outer peripheral portion of the deposit control ring such that an upper surface side of the deposit control ring projects radially outward, and
the gap has a labyrinth structure formed by the lower end portion and the upper end portion.
6. The stage according to claim 5 , wherein an inner diameter of an upper surface of the deposit control ring is larger than an outer diameter of the substrate disposed on the base, and
an interval between an inner peripheral surface on an upper surface side of the focus ring and an outer peripheral surface of the substrate is larger than 0 mm and equal to or less than 1 mm.
7. The stage according to claim 1 , wherein an inner diameter of the focus ring is smaller than an inner diameter of the adsorption electrode, and
a difference between the inner diameter of the focus ring and the inner diameter of the adsorption electrode is larger than 0 mm and equal to or less than 10 mm.
8. The stage according to claim 1 , wherein an outer diameter of the deposit control ring is 300 mm to 360 mm.
9. The stage according to claim 1 , wherein a material of the deposit control ring is different from a material of the focus ring and selected from a brittle material or a resin material.
10. The stage according to claim 1 , wherein the base includes:
a base body;
a substrate holder provided on the base body; and
a ring holder provided radially outside the substrate holder on the base body, wherein the focus ring is held on the ring holder, and
the deposit control ring is provided radially inside the ring holder on the base body.
11. The stage according to claim 1 , wherein a thermal resistance layer having a heat insulating property is formed between the deposit control ring and the base.
12. The stage according to claim 11 , wherein the thermal resistance layer is a heat insulating coating formed on at least a contact surface of the deposit control ring or a contact surface of the base.
13. The stage according to claim 11 , wherein the thermal resistance layer is a heat insulating member provided between the deposit control ring and the base.
14. The stage according to claim 1 , further comprising a heater configured to heat the substrate disposed on at least the focus ring or the base.
15. The stage according to claim 1 , wherein the base includes:
a base body;
a substrate holder provided on the base body; and
a ring holder provided radially outside the substrate holder on the base body, and wherein the focus ring and the deposit control ring are held on the ring holder.
16. The stage according to claim 15 , wherein the substrate holder and the ring holder are integrally constructed.
17. A plasma processing apparatus comprising:
a processing container that defines a processing space in which plasma is generated; and
a stage on which a substrate is disposed inside the processing container,
wherein the stage includes:
a base embedded with an adsorption electrode therein;
a focus ring provided above the adsorption electrode and adsorbed and held on the base; and
a deposit control ring provided radially inside the focus ring on the base, and
wherein a gap is formed between the focus ring and the deposit control ring in a radial direction to separate the focus ring and the deposit control ring.