Electrostatic chuck and its manufacturing method
An electrode pattern of an electrostatic chuck includes linear portions in a radial direction and a plurality of concentric C-shaped portions branching out from the linear portions. The linear portions are disposed opposite to each other in a diametrical direction and are such that they lie on a line that is almost straight. The C-shaped portions are engaged alternately like teeth of a comb.
1. A bipolar electrostatic chuck comprising:
a positive electrode and a negative electrode that are almost circular in shape,
the positive electrode and the negative electrode including linear portions extending in a radial direction and a plurality of concentric C-shaped portions branching from the linear portions; and
wafer lifting pins in a region that is between the adjacent C-shaped portions and that excludes the linear portions, wherein
the linear portions are substantially collinear and diametrically opposite each other, and have the C-shaped portions enmeshed with each other; and
the linear portions of the positive electrode and the negative electrode are each provided with at least one node therealong that is configured to supply power to said chuck.
2. A bipolar electrostatic chuck comprising:
a positive electrode and a negative electrode that are almost circular in shape, wherein:
the positive electrode and the negative electrode include a plurality of concentric C-shaped portions and a plurality of short linear portions radially connecting the C-shaped portions;
the C-shaped portions of the positive electrode and the negative electrode are enmeshed with each other;
the short linear portions connect C-shaped portions of the plurality of concentric C-shaped portions of the same polarity and at least one of said short linear portions is circumferentially offset with respect to others of said short linear portions; and
at least one of the plurality of short linear portions of the positive electrode and at least one of the plurality of short linear portions of the negative electrode are provided with a node configured to supply power to said chuck.
3. The electrostatic chuck according to claim 2 , further comprising wafer lifting pins in a region that is between the adjacent C-shaped portions and that excludes the linear portions.
4. An electrostatic chuck comprising:
a comma-shaped positive electrode and a comma-shaped negative electrode that are point symmetrical; and
a reverse S-shaped positive electrode and a reverse S-shaped negative electrode that are disposed between the comma-shaped positive electrode and the comma-shaped negative electrode, wherein
the reverse S-shaped positive electrode is adjacent to the comma-shaped negative electrode and the reverse S-shaped negative electrode is adjacent to the comma-shaped positive electrode.
5. The electrostatic chuck according to claim 4 , further comprising:
a node, to supply electric power, on a head portion of each of the comma-shaped positive electrode and the comma-shaped negative electrode; and
a node, to supply electric power, at a position approximately halfway along the reverse S-shaped positive electrode and the reverse S-shaped negative electrode.
6. The electrostatic chuck of claim 1 , wherein the nodes configured to supply power to said chuck are approximately midway along the linear portions of each of the positive electrode and the negative electrode.
7. The electrostatic chuck of claim 2 , wherein the nodes configured to supply power to said chuck are provided on one of the plurality of short linear portions of each of the electrodes which is both radially interior to at least a second one of the plurality of short linear portions of the same polarity, and radially exterior to at least a third one of the plurality of short linear portions of the same polarity.