Electrostatic chuck

• US 6,134,096 A
• Filed: 05/18/1999
• Issued: 10/17/2000
• Est. Priority Date: 09/06/1995
• Status: Expired due to Term

• Current Assignee: NGK Insulators Limited
• Original Assignee: NGK Insulators Limited
• Inventors: Yamada, Naohito, Ohno, Masashi, Ushikoshi, Ryusuke
• Primary Examiner(s): Jackson, Stephen W.
• Application Number:
  US09/317,772
• Time in Patent Office: 518 Days
• Field of Search: 361/230-235, 279/128
• US Class Current: 361/234
• CPC Class Codes: G03F 7/707 Chucks, e.g. chucking or un-chucking operations or structural details
• CPC Class Codes: G03F 7/70708 being electrostatic; Electrostatically deformable vacuum chucks
• CPC Class Codes: H01L 21/6833 Details of electrostatic chucks
• CPC Class Codes: Y10T 279/23 with magnetic or electrostatic means

Abstract

An electrostatic chuck for attracting an object for treatment. The electrostatic chuck includes a substrate, an insulating dielectric layer and at least one electrode located between the substrate and the insulating dielectric layer. The object is attracted onto the electrode via the insulating dielectric layer. The insulating dielectric layer is between 0.5 mm and 5.0 mm thick, and utilizes a gas-introducing hole to form a gas-diffusing depression on the side of an attractive surface, allowing for more uniform heat conduction. The gas-diffusing depression is between 100 um and 5.0 mm deep. The distance between the bottom surface of the gas-diffusing depression and an electrode may range from 500 μm to 5 mm.

Claims

1. An electrostatic chuck for attracting an object to be treated, comprising:

a substrate;

an insulating dielectric single layer comprising a ceramic material with a porosity level of not more than 3%; and

at least one electrode being formed on and in contact with a top surface of said substrate and the insulating dielectric single layer being formed on and in contact with a top surface of said at least one electrode;

wherein

said object is attracted onto said at least one electrode via the insulating dielectric layer;

said insulating dielectric single layer having an average thickness of 1 to 3 mm; and

said insulating dielectric layer is a ceramic material selected from the group consisting of silicon nitride, aluminum nitride, boron nitride, sialon, silicon carbide and alumina-silicon nitride material, said electrostatic chuck having a leaked current value of 0.0017 to 0.0100 mA/cm².

2. The electrostatic chuck set forth in claim 1, wherein each of said substrate and the insulating dielectric layer is comprised of a dense ceramic material, said at least one electrode is composed of a planar metallic bulky body, and the substrate, the insulating dielectric layer and at least one electrode are integrally sintered.

3. The electrostatic chuck set forth in claim 1, wherein a resistive heating element is buried in the substrate.

4. The electrostatic chuck set forth in claim 1, which further comprises a high frequency electric power source for feeding a high frequency electric power upon said at least one electrode so as to generate plasma upon said object.

5. An electrostatic chuck for attracting an object to be treated, comprising:

a substrate,

an insulating dielectric single layer having an average thickness of 1 to 3 mm,

and at least one electrode provided on and in contact with a top surface of said substrate, and the insulating dielectric layer being provided on and in contact with a top surface of said at least one electrode, wherein

said object to be treated is attracted onto said at least one electrode via the insulating dielectric single layer,

a gas-introducing hole being provided at least in said insulating dielectric single layer while being opened to an attracting surface of said insulating dielectric single layer, further including

at least one gas-diffusing depression being formed in said insulating dielectric single layer on a side of the attracting surface, and a depth of the gas-diffusing depression is not less than 100 μ

m and not more than 5.0 mm, said electrostatic chuck having a leaked current value of 0.0017 to 0.0100 mA/cm².

6. The electrostatic chuck set forth in claim 5, wherein said insulating dielectric layer is a material selected from the group consisting of silicon nitride, aluminum nitride, boron nitride, sialon, silicon carbide and alumina-silicon nitride material.

7. The electrostatic chuck set forth in claim 5, wherein said insulating dielectric single layer is comprised of a ceramic material with a porosity level of not more than 3%.

8. The electrostatic chuck set forth in claim 7 wherein said insulating dielectric layer is comprised of silicon nitride.

9. The electrostatic chuck set forth in claim 7, wherein said insulating dielectric layer is comprised of aluminum nitride.

10. The electrostatic chuck set forth in claim 5, wherein each of said substrate and said insulating dielectric single layer is comprised of a ceramic material with a porosity level of not more than 3%, said at least one electrode is composed of a planar metallic bulky body, and said substrate, said insulating dielectric single layer, and said at least one electrode are integrally sintered.

11. The electrostatic chuck set forth in claim 5, further comprising a resistive heating element buried in said substrate.

12. The electrostatic chuck set forth in claim 5, further comprising a high frequency electric power source for feeding a high frequency electric power upon said at least one electrode so as to generate plasma upon said object.