The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Mar. 22, 2022
Filed:
Dec. 17, 2019
Ngk Insulators, Ltd., Nagoya, JP;
Tatsuya Kuno, Nagoya, JP;
Ikuhisa Morioka, Handa, JP;
Takashi Kataigi, Handa, JP;
Kenichiro Aikawa, Handa, JP;
NGK Insulators, Ltd., Nagoya, JP;
Abstract
An electrostatic chuck includes a first ceramic member disk-shaped and having an annular step surface outside a circular wafer holding surface thereof, the annular step surface being at a lower level than the wafer holding surface, the first ceramic member having a volume resistivity that allows Coulomb force to be exerted; a first electrode embedded in the first ceramic member at a position facing the wafer holding surface; a second electrode disposed on the annular step surface of the first ceramic member, the second electrode being independent of the first electrode; and a second ceramic member having an annular shape and configured to cover the annular step surface having the second electrode thereon, the second ceramic member having a volume resistivity that allows Johnsen-Rahbek force to be exerted, wherein an upper surface of the second ceramic member is a focus ring holding surface on which a focus ring is placed.