Electro-Optic Materials by Solid Source MOCVD

Abstract

AbstractThe solid source MOCVD technique1,2, employing a single powder vaporization source composed of mixed beta-diketonate metalorganic compounds, has been used to grow thin films of a variety of electro-optic materials, including lithium niobate, strontium barium niobate, and potassium niobate. Results for potassium niobate films are quite preliminary, but indicate that a volatile potassium organometallic source can be synthesized which is useful for growing potassium niobate by MOCVD. High quality single phase (001) oriented strontium barium niobate films have been deposited which exhibit waveguiding behavior. The most extensive work has been done on lithium niobate, which has been deposited epitaxially on a variety of substrates. Oriented z-axis (001) films have been grown on c-axis sapphire with and without a (111) oriented platinum base electrode and on a bulk grown lithium niobate substrate. Films grown directly on c-axis sapphire at 700 C exhibit x-ray rocking curve linewidths as low as.044 degrees, nearly perfect in-plane orientation as determined by x-ray phi scans, and peak-to-peak surface roughness less than 40 Å. Optical waveguiding has been demonstrated by a single prism coupling technique on similar films 1175 – 2000 Å thick grown at 500 C, with optical losses of approximately 2 db/cm at 632.8 nm measured over 3.5 cm long films. Polarization vs. electric field measurements on 1100 Å thick films grown on platinum show a hysteresis loop indicating ferroelectric behavior.