PIEZOELECTRIC THIN FILM AND METHOD FOR PRODUCING SAME

摘要

A piezoelectric thin film (1) is formed through sputtering and consists essentially of scandium aluminum nitride. The carbon atomic content is 2.5 at% or less. When producing the piezoelectric thin film (1), scandium and aluminum are sputtered simultaneously on a substrate (21) from a scandium aluminum alloy target material (10) having a carbon atomic content of 5 at% or less in an atmosphere where at least nitrogen gas exists. The sputtering may be conducted also by applying an ion beam (31) on an opposing surface of the alloy target material at an oblique angle. Moreover, aluminum and scandium may be also sputtered simultaneously on the substrate from an Sc target material and an Al target material. As a result, a piezoelectric thin film which exhibits excellent piezoelectric properties and a method for the same can be provided.