| 摘要 |
PURPOSE:The titled wafer in which the fluctuation range of the optical birefringence in the wafer is specified, thus being suitable for making SAW devices with constant performances and qualities. CONSTITUTION:Melted lithium tantalate is pulled up according to the Chokralsky method to allow its single crystal to grow and the resultant single crystal is subjected to polarization treatment to prepare a single domain ferroelectric material. Then, the material is processed into a cylinder, cut into wafers with a certain crystal surface orientation and abraded to give single crystal wafers of lithium tantalate with a fluctuation range of 4.5X10<-3>+ or -6X10<-4> in optical birefringence measured using light of 0.6328mum wavelength at 20 deg.C in the wafer. |
