Aluminum nitride substrate and thin film substrate therewith, and manufacturing method thereof

摘要

An aluminum nitride substrate includes an aluminum nitride sintered body containing a rare earth oxide as a sintering additive component. In the aluminum nitride substrate, a surface thereof is machined so that arithmetic average roughness Ra is 0.5 mum or less; an aggregate size of the sintering additive component present on the machined surface is 20 mum or less; and a total aggregate area in a unit area of the machined surface is 5% or less. A metal thin film is deposited on such machined surface with good intimate contact properties, and furthermore deposition accuracy or the like is improved.