Focus ring and substrate processing apparatus including the same

A substrate processing apparatus, comprising:

• an electrostatic chuck;
• a focus ring on the electrostatic chuck;
• and
• an outer ring that surrounds the focus ring,
• wherein the focus ring includes:
• a first ring;
• and
• a second ring,
• wherein the first ring includes:
• a first ring body;
• and
• a protrusion member that extends outwardly from the first ring body,
• wherein:
• a top-most surface of the protrusion member is at a vertical level lower than a vertical level of a top-most surface of the first ring body,
• a first portion of the second ring is on the protrusion member,
• a second portion of the second ring is on the outer ring,
• the first ring body has an outer lateral surface that slopes downwardly and outwardly,
• the second ring has an inner lateral surface that slopes downwardly and outwardly,
• with respect to a vertical line, an inclination of the outer lateral surface is greater than an inclination of the inner lateral surface, and
• a bottom surface of the second ring is vertically spaced apart from and not in contact with the top-most surface of the protrusion member to form a gap between the second ring and the protrusion member.

A substrate processing apparatus, comprising:

• an electrostatic chuck;
• a focus ring on the electrostatic chuck;
• and
• a ring lift pin that extends in a first direction,
• wherein the focus ring includes:
• a first ring formed around an axis that is parallel to the first direction;
• and
• a second ring not affixed to the first ring,
• wherein:
• the ring lift pin is disposed below the second ring,
• a portion of an inner lateral surface of the second ring contacts a portion of an outer lateral surface of the first ring, and
• a first acute angle between the first direction and a line formed by the outer lateral surface when viewed in a cross-sectional view from a direction perpendicular to the axis is different from a second acute angle between the first direction and a line formed by the inner lateral surface when viewed in the cross-sectional view from the direction perpendicular to the axis.