Ceramic joined body, substrate holding structure and substrate processing apparatus

Abstract

A substrate holding structure having excellent corrosion resistance and airtightness, excellent dimensional accuracy and sufficient durability when mechanical or thermal stress is applied thereto is obtained. A holder () serving as the substrate holding structure includes a ceramic base () for holding a substrate, a protective cylinder () joined to the ceramic base () and a joining layer () positioned therebetween for joining the ceramic base () and the protective cylinder () to each other. The joining layer () contains at least 2 mass % and not more than 70 mass % of a rare earth oxide, at least 10 mass % and not more than 78 mass % of aluminum oxide, and at least 2 mass % and not more than 50 mass % of aluminum nitride. The rare earth oxide or the aluminum oxide has the largest proportional content among the aforementioned three types of components in the joining layer ().