Patent ID: 7258742

Claim:
A method of manufacturing potassium niobate single crystal thin film by vapor deposition, comprising the steps of: supplying a material in a gas phase to a substrate so that a value of x is in a range 0.5≦x≦x E immediately after deposition of the material on the substrate, where the x E is a mole composition ratio at a eutectic point E for KNbO 3 and 3K 2 O.Nb 2 O 5 under a predetermined oxygen partial pressure, and the x is a mole ratio of niobium (Nb) to potassium (K) in K x Nb 1−x O y ; precipitating potassium niobate single crystal while maintaining a temperature T s of the substrate in a range T E ≦T s ≦T m , where T E is a temperature at the eutectic point, and T m is a complete melting temperature at the oxygen partial pressure and at the value of x in the range; and evaporating a liquid phase portion from the K x Nb 1−x O y where a solid phase portion and a liquid phase portion coexist.