Patent 7948735 was granted and assigned to NGK Insulators on May, 2011 by the United States Patent and Trademark Office.
The electrostatic chuck includes a base including an aluminum nitride-containing member; a dielectric layer formed on the base including a member having a volume resistivity of at least 1×1015 Ω·cm at a temperature range of about 25° C. to about 300° C. and including 2 to 5% by mass of yttrium oxide, 2 to 5% by mass of ytterbium oxide, and a balance of aluminum nitride based on the total mass of the dielectric layer; and an electrode embedded under the dielectric layer so as to be positioned between the dielectric layer and the base, configured to generate an electrostatic absorption force.