Electrostatic holding apparatus

• US 6,122,159 A
• Filed: 12/10/1998
• Issued: 09/19/2000
• Est. Priority Date: 12/12/1997
• Status: Expired due to Term

• Current Assignee: Shin-Etsu Chemical Company Limited
• Original Assignee: Shin-Etsu Chemical Company Limited
• Inventors: Kubota, Yoshihiro, Arai, Kenichi
• Primary Examiner(s): SHERRY, MICHAEL JUDE
• Application Number:
  US09/209,703
• Time in Patent Office: 649 Days
• Field of Search: 361/230-235, 279/128
• US Class Current: 361/234
• CPC Class Codes: H01L 21/6833 Details of electrostatic chucks
• CPC Class Codes: Y10T 279/23 with magnetic or electrostatic means

Abstract

An electrostatic holding apparatus in which a voltage is applied to an conductive electrode covered with an insulating dielectric layer, in order to cause the insulating dielectric layer to electrostatically attract an object. The insulating dielectric layer is substantially formed of a sintered body produced by addition of 2.5-5 wt. % titania (TiO₂) and 5 wt. % or less titanium nitride (TiN) powder to powder of a high resistivity ceramic having a volume resistivity of 1×10¹⁴ Ω·cm or higher at 25° C., followed by kneading, forming, and sintering. The sintered body has a volume resistivity of 1×10⁸ -8×10¹³ Ω·cm at 25° C. The volume resistivity of the insulating dielectric layer is decreased so as to increase an electrostatic attraction force, and an object can be removed at the time of stopping application of voltage. Further, the electrostatic holding apparatus does not generate impurities that would otherwise contaminate semiconductor devices. In addition, neither fine cracks nor pores remain, so that the electrostatic holding apparatus excellent in terms of withstand voltage.

Claims

1. An electrostatic holding apparatus for electrostatically attract an object when applied with a voltage, the apparatus comprising:

an electrode to be applied with the voltage; and

an insulating dielectric layer covering the electrode,

wherein the insulating dielectric layer is formed of a sintered body having a volume resistivity of 1×

10⁸ to 8×

10¹³ Ω

·

cm at 25°

C. and containing a high resistivity ceramic, 2.5 to 5 wt. % of titania (TiO₂) and 5 wt. % or less of titanium nitride (TiN), wherein the high resistivity ceramic has a volume resistivity of 1×

10¹⁴ Ω

·

cm or higher at 25°

C.

2. The electrostatic holding apparatus of claim 1, wherein the high resistivity ceramic is one or more ceramic materials selected from a group consisting of alumina, aluminum nitride, and zirconium oxide.