Densification and high thermal conductivity of AlN ceramics

Abstract

AlN is characterized by a high thermal conductivity, excellent electrical insulation and excellent corrosion resistance to halogen and plasma, and applied for substrates to the semiconductor devices, the fabrication equipment for silicon semiconductor and fillers for resin substrates. However, it decomposes to Al and N at about 2200 degree C without melting, because of its high covalent bond structure. Therefore, it has been recognized as an unsinterable material. Author found in around 1970 that rare esarth oxides and alkali earth oxides are good sintering aids. Most recently AlN-Y₂O₃ has been widely used to fabricate the high thermal conductive AlN ceramics. In this text, densification and high thermal conductivity of AlN ceramics will be introduced according to the historical flow.