US 12,243,764 B2
Electrostatic chuck
Hiroshi Takebayashi, Handa (JP); and Yuma Iwata, Ichinomiya (JP)
Assigned to NGK INSULATORS, LTD., Nagoya (JP)
Filed by NGK INSULATORS, LTD., Nagoya (JP)
Filed on Jun. 25, 2021, as Appl. No. 17/304,749.
Application 17/304,749 is a continuation of application No. PCT/JP2020/009189, filed on Mar. 4, 2020.
Claims priority of application No. 2019-050246 (JP), filed on Mar. 18, 2019.
Prior Publication US 2021/0320025 A1, Oct. 14, 2021
Int. Cl. H01L 21/683 (2006.01)
CPC H01L 21/6833 (2013.01) 10 Claims
OG exemplary drawing
 
1. An electrostatic chuck comprising:
a ceramic plate having a wafer placement surface;
a plurality of through holes which penetrate the plate in a thickness direction; and
a pair of positive and negative electrodes provided in the plate to generate an electrostatic force,
wherein the plate has division areas virtually divided, which are equal in number to a number of the through holes,
the pair of positive and negative electrodes have pairs of positive and negative helical electrode portions, and for each of the division areas, one of the pairs of positive and negative helical electrode portions is provided in parallel to each other so as to cover an entirety of the division area from each of a positive electrode start point and a negative electrode start point, and wherein the positive electrode start point and the negative electrode start point for each division area are proximate to the through hole for the division area and with the through hole for each division area located between the positive electrode start point and the negative electrode start point in a circumferential direction of the plate,
the positive electrode of the pair of positive and negative electrodes is such that the positive helical electrode portions of the division areas are connected via either one of a triangular shaped connection portion provided at a central portion and an annular shaped connection portion provided at outer circumferential portions of the plate, and
the negative electrode of the pair of positive and negative electrodes is such that the negative helical electrode portions of the division areas are connected via the other of the triangular shaped connection portion provided at the central portion and the annular shaped connection portion provided at the outer circumferential portions of the plate.