Growth and characterization of c-axis oriented LiNbO_3 film on a transparent conducting Ah : ZnO inter-layer on Si

摘要

C-axis oriented lithium niobate (LiNbO_3) films were deposited by pulsed-laser deposition on silicon using a transparent conducting interlayer of aluminum (Al)-doped zinc oxide (ZnO). Only two x-ray diffraction reflections corresponding to (006) and (0012) planes of LiNbO_3 were observed in the films deposited at a 100-mTorr oxygen pressure and a 450-500 deg C substrate temperature. Presence of sharp modes corresponding to E(TO) and A(LO), and absence of any superfluous peaks mainly around 900-905 cm~(-1) in the Raman spectra confirmed the formation of textured LiNbO_3 film. Measured value of direct current and alternate current (AC) conductivities and dielectric constant are 8.6 X 10~(-12) OMEGA ~(-1) cm~(-1), 1.16 X 10~(-6) OMEGA ~(-1) cm~(-1), and 29.3, respectively, at room temperature. Behavior of dielectric constant and AC conductivity with frequency and temperature are close to the reported single-crystal data.