Dielectric material and electrostatic chucking device

• US 9,944,561 B2
• Filed: 03/09/2015
• Issued: 04/17/2018
• Est. Priority Date: 03/10/2014
• Status: Active Grant

• Current Assignee: Sumitomo Osaka Cement Company Limited
• Original Assignee: Sumitomo Osaka Cement Company Limited
• Inventors: Ishizuka, Masayuki, Nagatomo, Hiroaki
• Primary Examiner(s): TRAN, THIENVU V
• Assistant Examiner(s): Comber, Kevin J
• Application Number:
  US15/120,150
• Publication Number:
  US 20170057875A1
• Time in Patent Office: 1,135 Days
• Field of Search: 361234
• CPC Class Codes: C04B 2235/3217 Aluminum oxide or oxide forming salts thereof, e.g. bauxite, alpha-alumina
• CPC Class Codes: C04B 2235/3225 Yttrium oxide or oxide-forming salts thereof
• CPC Class Codes: C04B 2235/3826 Silicon carbides
• CPC Class Codes: C04B 2235/404 Refractory metals
• CPC Class Codes: C04B 2235/422 Carbon
• CPC Class Codes: C04B 2235/5445 submicron sized, i.e. from 0,1 to 1 micron
• CPC Class Codes: C04B 2235/5472 Bimodal, multi-modal or multi-fraction
• CPC Class Codes: C04B 2235/606 Drying
• CPC Class Codes: C04B 2235/6567 Treatment time
• CPC Class Codes: C04B 2235/658 Atmosphere during thermal treatment
• CPC Class Codes: C04B 2235/66 Specific sintering techniques, e.g. centrifugal sintering
• CPC Class Codes: C04B 2235/764 Garnet structure A3B2(CO4)3
• CPC Class Codes: C04B 2235/80 Phases present in the sintered or melt-cast ceramic products other than the main phase
• CPC Class Codes: C04B 35/01 based on oxide ceramics
• CPC Class Codes: C04B 35/117 Composites
• CPC Class Codes: C04B 35/14 based on silica
• CPC Class Codes: C04B 35/185 Mullite 3Al2O3-2SiO2
• CPC Class Codes: C04B 35/44 based on aluminates
• CPC Class Codes: C04B 35/488 Composites
• CPC Class Codes: C04B 35/495 based on vanadium, niobium, tantalum, molybdenum or tungsten oxides or solid solutions thereof with other oxides, e.g. vanadates, niobates, tantalates, molybdates or tungstates
• CPC Class Codes: C04B 35/50 : based on rare-earth compounds non-oxide rare earth compounds C04B35/5156
• CPC Class Codes: C04B 35/505 : based on yttrium oxide
• CPC Class Codes: C04B 35/581 : based on aluminium nitride
• CPC Class Codes: C04B 35/583 : based on boron nitride
• CPC Class Codes: C04B 35/584 : based on silicon nitride
• CPC Class Codes: C04B 35/6261 : Milling
• CPC Class Codes: C04B 35/62625 : Wet mixtures
• CPC Class Codes: C04B 35/6264 : Mixing media, e.g. organic solvents
• CPC Class Codes: C04B 35/62655 : Drying, e.g. freeze-drying, spray-drying, microwave or supercritical drying
• CPC Class Codes: C04B 35/645 : Pressure sintering
• CPC Class Codes: C04B 35/6455 : Hot isostatic pressing
• CPC Class Codes: C04B 35/78 : containing non-metallic materials
• CPC Class Codes: H01B 3/004 : with conductive additives or conductive layers
• CPC Class Codes: H01L 21/6833 : Details of electrostatic chucks
• CPC Class Codes: H02N 13/00 : Clutches or holding devices using electrostatic attraction, e.g. using Johnson-Rahbek effect

Abstract

A dielectric material includes a composite sintered body in which conductive particles are dispersed in an insulating material, in which a dielectric constant at a frequency of 40 Hz is 10 or higher, and a difference between a maximum dielectric loss value and a minimum dielectric loss value at a frequency of 1 MHz in a surface of the composite sintered body is 0.002 or less.

Claims

1. A dielectric material, wherein

the dielectric material is a composite sintered body in which conductive particles are dispersed in an insulating material,

the insulating material is at least one selected from the group consisting of aluminum oxide and yttrium oxide,

the conductive particles are silicon carbide particles,

the content of the conductive particles in the dielectric material is 4 to 20% by mass,

the conductive particles are a mixed conductive particles wherein plural kinds of conductive particles having different average particle diameters are mixed,

the mixture of conductive particles includes 1 to 40% by mass of conductive particles having a particle diameter of 40 nm or less and 1 to 40% by mass of the conductive particles having a particle diameter of 80 nm or more,

a dielectric constant of the dielectric material at a frequency of 40 Hz is 10 or higher, and

a difference between a maximum value and a minimum value of dielectric loss of the dielectric material wherein the dielectric loss is measured at a frequency of 1 MHz on the surface of the composite sintered body is 0.002 or less,

a volume resistivity at 20°

C. of the dielectric material is 10¹³ Ω

·

cm or higher.

2. The dielectric material according to claim 1,

wherein a withstand voltage at 20°

C. of the dielectric material is 5 kV/mm or higher.

3. The dielectric material according to claim 1,

wherein a thermal conductivity of the dielectric material is 20 W/m·

K or higher.

4. The dielectric material according to claim 1,

wherein dielectric loss at a frequency of 40 Hz of the dielectric material is 0.01 or higher and 0.05 or lower.

5. An electrostatic chuck device comprising

a base having a main surface on which a plate-like sample is electrostatically attracted,

wherein the base is formed of the dielectric material according to claim 1.