Wafer support table
A wafer support table includes a ceramic base having a wafer placement surface, and a plurality of heaters embedded in the ceramic base. The ceramic base has a first heater formation surface, a second heater formation surface, and a third heater formation surface in a stated order from the wafer placement surface toward a surface opposite from the wafer placement surface. A first heater is provided on the first heater formation surface so as to be located at a center of the ceramic base. A second heater is provided on the second heater formation surface so as to be located around a periphery of the first heater. A third heater is provided on the third heater formation surface so as to overlap the second heater and is provided in each of a plurality of zones divided from the third heater formation surface by a radial line segment.
1 . A wafer support table comprising:
a ceramic base having a wafer placement surface; and
a plurality of heaters embedded in the ceramic base, wherein
the ceramic base has a first heater formation surface, a second heater formation surface, and a third heater formation surface in a stated order from the wafer placement surface toward a surface opposite from the wafer placement surface,
the plurality of heaters includes a first heater provided on the first heater formation surface, a second heater provided on the second heater formation surface, and a third heater provided on the third heater formation surface,
the first heater is provided so as to be located at a center of the ceramic base,
the second heater is provided so as to be located around a periphery of the first heater, and
the third heater is provided so as to overlap the second heater and is provided in each of a plurality of zones divided from the third heater formation surface by a radial line segment, and
wherein the first heater, the second heater, and the third heater each have a coil shape, and a second heater jumper is connected to a surface side opposite from the wafer placement surface with respect to a coil center of the second heater, and a third heater jumper is connected to a side closer to the wafer placement surface with respect to a coil center of the third heater,
wherein the second heater jumper is not electrically connected to the third heater jumper, and
wherein a distance from the third heater jumper to the surface side opposite from the wafer placement surface is greater than a distance from the second heater jumper to the wafer placement surface.
2 . The wafer support table according to claim 1 , wherein the second heater jumper is provided on the second heater formation surface, and the third heater jumper is provided on the third heater formation surface.
3 . The wafer support table according to claim 1 , wherein
terminal holes for respectively supplying electricity to the first heater, the second heater, and the third heater get deeper in proportion to depths of the associated heaters.
4 . The wafer support table according to claim 1 , wherein the ceramic base has an RF electrode disposed closer to the wafer placement surface than the plurality of heaters and has a cylindrical shaft on the surface opposite from the wafer placement surface, and a rod that supplies electricity to the first heater, a rod that supplies electricity to the second heater, a rod that supplies electricity to the third heater, and a rod connected to the RF electrode respectively have parts protruding from the shaft with the same length.
5 . The wafer support table according to claim 1 , wherein
the second heater is provided in each of a plurality of zones divided from the second heater formation surface by a boundary concentric with the ceramic base.