Electrostatic chuck and susceptor
An electrostatic chuck fixing a workpiece disposed on a mounting surface via electrostatic attraction with application of a voltage to an electrode buried inside the electrostatic chuck comprises: the mounting surface having an uneven structure including a plurality of protrusions two-dimensionally spaced apart with predetermined pitches and a depression that is flat between the protrusions, each of the protrusions includes: a flat portion having a flat surface being vertical in a thickness direction of the electrostatic chuck and having a uniform height; and a sloped portion around the flat portion having a height decreasing from the flat portion toward the depression, and the sloped portion has an upper surface with a slope angle of 65 degrees or higher and 84 degrees or lower in the thickness direction of the electrostatic chuck.
1 . An electrostatic chuck fixing a workpiece via electrostatic attraction, the electrostatic chuck comprising:
a mounting surface on which the workpiece is disposed; and
an electrostatic chuck electrode which is buried inside the electrostatic chuck and to which a voltage is applied so that the workpiece disposed on the mounting surface is fixed via electrostatic attraction,
wherein the mounting surface has an uneven structure including a plurality of protrusions two-dimensionally spaced apart with predetermined pitches, and a depression that is flat between the protrusions,
each of the protrusions includes:
a flat portion having a flat surface, the flat surface being vertical to a thickness direction of the electrostatic chuck and all of the flat surfaces of the protrusions having a same uniform height; and
a sloped portion around the flat portion, the sloped portion having a height decreasing from the flat portion toward the depression, and
the sloped portion has an upper surface with a slope angle of 65 degrees or higher and 84 degrees or lower to the thickness direction of the electrostatic chuck.
2 . The electrostatic chuck according to claim 1 ,
wherein the protrusions are tapered in a cross-sectional view.
3 . The electrostatic chuck according to claim 2 ,
wherein each of the protrusions is continuous with at least one of the flat portion or the depression via a curved surface.
4 . The electrostatic chuck according to claim 1 ,
wherein each of the flat portions is shaped like a circle in a plan view, and
each of the sloped portions is shaped like a ring in the plan view.
5 . The electrostatic chuck according to claim 1 ,
wherein each of the flat portions has a height ranging from 10 μm to 50 μm from the depression.
6 . A susceptor, comprising:
an electrostatic chuck fixing a workpiece via electrostatic attraction; and
a cooling plate bonded to the electrostatic chuck, the cooling plate including
a fluid channel through which a coolant is cyclically supplied to allow the cooling plate to cool the workpiece,
the electrostatic chuck including:
a mounting surface on which the workpiece is disposed;
an electrostatic chuck electrode which is buried inside the electrostatic chuck and to which a voltage is applied so that the workpiece disposed on the mounting surface is fixed via electrostatic attraction; and
a heater electrode buried inside the electrostatic chuck,
wherein the mounting surface has an uneven structure including a plurality of protrusions two-dimensionally spaced apart with predetermined pitches, and a depression that is flat between the protrusions,
each of the protrusions includes:
a flat portion having a flat surface, the flat surface being vertical to a thickness direction of the electrostatic chuck and all of the flat surfaces of the protrusions having a same uniform height; and
a sloped portion around the flat portion, the sloped portion having a height decreasing from the flat portion toward the depression, and
the sloped portion has an upper surface with a slope angle of 65 degrees or higher and 84 degrees or lower to the thickness direction of the electrostatic chuck.
7 . A susceptor, comprising:
an electrostatic chuck fixing a workpiece via electrostatic attraction; and
a hollow shaft attached to the electrostatic chuck,
the electrostatic chuck including:
a mounting surface on which the workpiece is disposed;
an electrostatic chuck electrode which is buried inside the electrostatic chuck and to which a voltage is applied so that the workpiece disposed on the mounting surface is fixed via electrostatic attraction; and
a heater electrode buried inside the electrostatic chuck,
wherein the mounting surface has an uneven structure including a plurality of protrusions two-dimensionally spaced apart with predetermined pitches, and a depression that is flat between the protrusions,
each of the protrusions includes:
a flat portion having a flat surface, the flat surface being vertical to a thickness direction of the electrostatic chuck and all of the flat surfaces of the protrusions having a same uniform height; and
a sloped portion around the flat portion, the sloped portion having a height decreasing from the flat portion toward the depression, and
the sloped portion has an upper surface with a slope angle of 65 degrees or higher and 84 degrees or lower to the thickness direction of the electrostatic chuck.
8 . The electrostatic chuck according to claim 2 ,
wherein each of the flat portions is shaped like a circle in a plan view, and
each of the sloped portions is shaped like a ring in the plan view.
9 . The electrostatic chuck according to claim 3 ,
wherein each of the flat portions is shaped like a circle in a plan view, and
each of the sloped portions is shaped like a ring in the plan view.
10 . The electrostatic chuck according to claim 2 ,
wherein each of the flat portions has a height ranging from 10 μm to 50 μm from the depression.
11 . The electrostatic chuck according to claim 3 ,
wherein each of the flat portions has a height ranging from 10 μm to 50 μm from the depression.
12 . The electrostatic chuck according to claim 4 ,
wherein each of the flat portions has a height ranging from 10 μm to 50 μm from the depression.
13 . The electrostatic chuck according to claim 8 ,
wherein each of the flat portions has a height ranging from 10 μm to 50 μm from the depression.
14 . The electrostatic chuck according to claim 9 ,
wherein each of the flat portions has a height ranging from 10 μm to 50 μm from the depression.
15 . The susceptor according to claim 6 ,
wherein the protrusions are tapered in a cross-sectional view.
16 . The susceptor according to claim 15 ,
wherein each of the protrusions is continuous with at least one of the flat portion or the depression via a curved surface.
17 . The susceptor according to claim 6 ,
wherein each of the flat portions is shaped like a circle in a plan view, and
each of the sloped portions is shaped like a ring in the plan view.
18 . The susceptor according to claim 7 ,
wherein the protrusions are tapered in a cross-sectional view.
19 . The susceptor according to claim 18 ,
wherein each of the protrusions is continuous with at least one of the flat portion or the depression via a curved surface.
20 . The susceptor according to claim 7 ,
wherein each of the flat portions is shaped like a circle in a plan view, and
each of the sloped portions is shaped like a ring in the plan view.