US 12,444,586 B2
Wafer placement table
Seiya Inoue, Handa (JP); Tatsuya Kuno, Nagoya (JP); and Ikuhisa Morioka, Handa (JP)
Assigned to NGK INSULATORS, LTD., Nagoya (JP)
Filed by NGK Insulators, Ltd., Nagoya (JP)
Filed on Feb. 9, 2023, as Appl. No. 18/166,585.
Claims priority of application No. 2022-058340 (JP), filed on Mar. 31, 2022.
Prior Publication US 2023/0317433 A1, Oct. 5, 2023
Int. Cl. H01J 37/32 (2006.01); H01L 21/683 (2006.01)
CPC H01J 37/32724 (2013.01) [H01L 21/6833 (2013.01); H01J 2237/002 (2013.01); H01J 2237/2007 (2013.01)] 6 Claims
OG exemplary drawing
 
1. A wafer placement table comprising:
a ceramic plate having a wafer placement surface on its upper surface and incorporating an electrode;
an electrically conductive plate provided on a lower surface side of the ceramic plate;
an electrically conductive bonding layer that bonds the ceramic plate with the electrically conductive plate;
a gas intermediate passage embedded in the electrically conductive bonding layer or provided at an interface between the electrically conductive bonding layer and the electrically conductive plate;
a plurality of gas supply passages extending from the gas intermediate passage through the electrically conductive bonding layer and the ceramic plate to the wafer placement surface;
a gas introduction passage provided so as to extend through the electrically conductive plate in an up and down direction and communicate with the gas intermediate passage, the number of the gas introduction passages being smaller than the number of gas supply passages constituting the plurality of gas supply passages communicating with the gas intermediate passage and
refrigerant flow channels in the electrically conductive plate formed in a one-stroke pattern with multiple circles over the area of the electrically conductive plate;
wherein each of the gas intermediate passages has an overlapping part that overlaps the refrigerant flow channel along the refrigerant flow channel in plan view;
wherein the gas supply passages each have an electrically insulating plug;
wherein each of the gas supply passages has a bonding layer penetrating part extending through the electrically conductive bonding layer and a ceramic plate penetrating part extending through the ceramic plate;
wherein a diameter of the bonding layer penetrating part is less than a diameter of the ceramic plate penetrating part; and
wherein a lower end of the electrically insulating plug is in contact with an area around the bonding layer penetrating part in the electrically conductive bonding layer.