SPUTTERING TARGET AND PROCESS FOR PRODUCING THE SAME

摘要

This invention provides a sputtering target that has low refractive index and, at the same time, low bulk resistance. The sputtering target comprises Al<SUB>2</SUB>O<SUB>3</SUB>: 0.2 to 3.0 at% and MgO and/or SiO<SUB>2</SUB>: 1 to 27 at% with the balance consisting of ZnO. There is also provided a process for producing a sputtering target having low refractive index and, at the same time, low bulk resistance, characterized by comprising previously mixing Al<SUB>2</SUB>O<SUB>3</SUB> powder and ZnO powder as raw materials, calcining the mixture, mixing the calcined Al<SUB>2</SUB>O<SUB>3</SUB>-ZnO mixed powder with MgO and/or SiO<SUB>2</SUB> powder, and then sintering the mixture. Further, a target for optical thin film formation, which is free from sulfur, has low bulk resistance, can realize DC sputtering, has low refractive index, and a process for producing the same are also provided. The target has high transmittance and is formed of a non-sulfide system and thus is useful for the formation of a thin film for an optical information recording medium that adjacent reflective layer and recording layer are less likely to be deteriorated. Further, improved properties of the optical information recording medium, reduced equipment cost, and significantly improved throughput by virtue of an improved film formation speed can be realized.