Wafer support
A wafer support of the present invention includes shield sheet embedded in the ceramic base between the plasma generation electrode and the heater electrode in a state not contacting both the electrodes; and a shield pipe electrically connected to the shield sheet and laid to extend to outside of the ceramic base from the surface of the ceramic base on the side opposite to the wafer placement surface, wherein the wiring member for the plasma generation electrode is inserted through inside of the shield pipe in a state not contacting the shield pipe, and the wiring member for the heater electrode is disposed outside the shield pipe in a state not contacting the shield pipe.
1. A wafer support comprising:
a ceramic base having an upper surface defining a wafer placement surface and a lower surface opposing the wafer placement surface;
a plasma generation electrode embedded in the ceramic base proximate the wafer placement surface;
a shield sheet embedded in the ceramic base between the plasma generation electrode and the lower surface;
at least one heater electrode embedded in the ceramic base between the shield sheet and the lower surface;
a conductive mesh shield pipe electrically connected to the shield sheet, having an outer peripheral surface and an inner peripheral surface, the inner peripheral surface defining a first space, and extending from the shield sheet through the lower surface of the ceramic base;
a shaft supporting the ceramic base and provided around the conductive mesh shield pipe, the shaft defining a second space between the shaft and the conductive mesh shield pipe, a bottom end of the shaft being supported on a columnar member, wherein the columnar member is conductive;
a conductive rod extending through the first space within the conductive mesh shield pipe, having a proximal end and a distal end, the proximal end being electrically connected to the plasma generation electrode;
a conductive socket embedded in an upper surface of the columnar member receiving therein the distal end of the conductive rod;
a conductive expansion bellows disposed around the conductive socket in a ring-shaped hole in the upper surface of the columnar member and electrically connected to the bottom of the conductive mesh shield pipe;
a first wiring member electrically connected to the at least one heater electrode and extending through the second space within the shaft and spaced away from contact with the conductive mesh shield pipe; and
at least one second wiring member electrically connected to the at least one heater electrode extending through the second space within the shaft and spaced away from contact with the conductive mesh shield pipe;
wherein the conductive mesh shield pipe comprises a material configured to prevent an RF electric field generated around the conductive rod from coupling with the at least one of the first and second wiring members; and,
wherein the conductive rod is electrically connected to an RF power source via the conductive socket which is electrically insulated from the columnar member.
2. The wafer support according to claim 1 , wherein the wiring members for the at least one heater electrode include a low pass filter between the at least one heater electrode and an external power supply.
3. The wafer support according to claim 1 , wherein the shield sheet is a planar member made of a mesh, a punching metal, or a metal plate, and
the conductive mesh shield pipe is made of a punching metal or a metal plate.
4. The wafer support according to claim 1 , wherein the plasma generation electrode is an electrode for applying a voltage of the RF power source, or a ground electrode.
5. The wafer support according to claim 1 , wherein a frequency of an RF current flowing in the plasma generation electrode is 13 MHz or higher.