| abstract |
This ceramic substrate is formed from a polycrystalline ceramic and has a supporting main surface. The supporting main surface has a roughness of 0.01 nm to 3.0 nm, in terms of Sa. On the supporting main surface, in a square region that is 50 μm per side, there are, on average, less than 5 convexities/concavities of at least 1 nm, and, on average, less than 1 convexity/concavity of at least 2 nm. |