Alumina-based sintered body and electrostatic chuck
AssigneeNiterra Co., Ltd.
InventorsMotoki Hotta, Takayuki Matsuoka, Takamichi Ogawa
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Abstract
In an alumina-based sintered body containing alumina (Al2O3) as a main component and containing magnesia (MgO) whose content with respect to a content of the alumina is 0.00 mol %<MgO≤0.20 mol %, a density is 3.96 g/cm3 or greater, and a standard deviation of grain sizes of alumina crystal grains is smaller than 4.0 μm.
Claims10
An alumina-based sintered body containing alumina (Al2O3) as a main component and containing magnesia (MgO) whose content with respect to a content of the alumina is 0.00 mol % <MgO≤0.20 mol %, wherein
- a density is 3.96 g/cm3 or greater, and a standard deviation of grain sizes of alumina crystal grains is smaller than 4.0 μm, a presence quantity of voids is 0.050 pieces/μm2 or less, and
- when the voids are divided into first voids which are voids present at crystal grain boundaries and second voids which are voids present in crystal grains, a ratio of a presence quantity of the second voids to the presence quantity of the voids is 20% or greater.
An alumina-based sintered body containing alumina (Al2O3) as a main component, wherein
- a presence quantity of voids is 0.050 pieces/μm2 or less, and
- when the voids are divided into first voids which are voids present at crystal grain boundaries and second voids which are voids present in crystal grains, a ratio of a presence quantity of the second voids to the presence quantity of the voids is 20% or greater.
An alumina-based sintered body containing alumina (Al2O3) as a main component and containing magnesia (MgO) whose content with respect to a content of the alumina is 0.00 mol % <MgO≤0.20 mol %, wherein
- a density is 3.96 g/cm3 or greater,
- a standard deviation of grain sizes of alumina crystal grains is smaller than 4.0 μm, and
- a dielectric breakdown voltage is 200 kV/mm or greater.
Dependencies are inferred from the claim text.