Plasma-resistant two-layer coating film structure and manufacturing method thereof

A plasma-resistant two-layer coating film structure comprising:

• a ceramic or metal substrate having pits on a surface thereof;
• a first coating layer which is a ceramic coating layer formed without cracks on the surface of the substrate by a spray coating method other than thermal spray, the layer being coated to fill the pits on the surface of the substrate, fine pits accompanying ceramic particle bonding being formed on the surface, and the layer including ceramic polycrystalline bodies having a crystallite size of less than 300 nm;
• and
• a second coating layer which is a plasma resistant ceramic film coated by one method of chemical vapor deposition (CVD), physical vapor deposition (PVD), and atomic layer deposition (ALD), the layer being formed to have a surface roughness (Ra) of 0.2 μm or less without a separate grinding process and coated to cover the fine pits to form a surface in which positions that may serve as starting points of plasma etching are minimized, and the layer being crystalline or in a mixed state where both a crystalline phase and an amorphous phase are present.