	US 11,887,873 B2
	Wafer placement apparatus
Keita Mine, Handa (JP); and Takumi Wakisaka, Takahama (JP)
Assigned to NGK INSULATORS, LTD., Nagoya (JP)
Filed by NGK INSULATORS, LTD., Nagoya (JP)
Filed on Mar. 18, 2020, as Appl. No. 16/822,541.
Claims priority of application No. 2019-058284 (JP), filed on Mar. 26, 2019.
Prior Publication US 2020/0312684 A1, Oct. 1, 2020
Int. Cl. H01L 21/67 (2006.01); H01L 21/673 (2006.01); H01L 21/683 (2006.01); H01B 3/28 (2006.01); H05B 3/28 (2006.01)

CPC H01L 21/67109 (2013.01) [H01L 21/673 (2013.01); H01L 21/6833 (2013.01); H01L 21/6835 (2013.01); H05B 3/283 (2013.01); H05B 2203/016 (2013.01); H05B 2203/017 (2013.01)]

6 Claims

1. A wafer placement apparatus comprising:

a ceramic plate having an upper surface as a wafer placement surface and in which an electrode is embedded; and

a cooling plate provided on a lower surface, opposite the wafer placement surface, of the ceramic plate and a refrigerant passage is provided in the cooling plate, wherein

the refrigerant passage includes a first passage and a second passage, with each passage forming a single continuous line having an overall length that extends between a respective inlet and outlet of the passage, the first passage and the second passage extend along a single common plane that is parallel to the wafer placement surface so as to have an uppermost axial surface of both the first and the second passages be at a same axial distance from the wafer placement surface, and the first and the second passages are formed directly adjacent to each other as a pair that have a substantially same size radial gap therebetween that extends across an entirety of the overall length of the first and the second passages, which includes the respective inlet and outlet of the first and the second passages, and

the inlet of the first passage, the outlet of the second passage, the inlet of the second passage, and the outlet of the first passage are linearly adjacent to one another in that order in a central part of the cooling plate.