Epitaxial Growth of MgO-doped Lithium Niobate Thin Films by Metalorganic Chemical Vapor Deposition

Abstract

Epitaxial MgO-doped lithium niobate [LiNbO 3 (LN)] single-crystal thin films with a good surface morphology and crystallinity were grown on lithium tantalate [LiTaO 3 (LT)] substrates by low-pressure metalorganic chemical vapor deposition (MOCVD). Dipivaloylmethanatolithium [Li(C 11 H 19 O 2 ); Li(DPM)], pentaethoxyniobium [Nb(OC 2 H 5 ) 5 ; Nb(OEt) 5 ] and bisacetylacetonatomagnesium [Mg(C 5 H 7 O 2 ) 2 ; Mg(Acac) 2 ] were used as volatile metalorganic precursors. The crystallinity of the films was investigated by X-ray diffraction measurements. Reciprocal space mapping indicated that good epitaxial growth had been achieved. The film surface was sufficiently smooth to act as a waveguide. The ordinary and extraordinary refractive indices (n o and n e ) of these as-grown MgO-doped LN thin films were measured to be n o ¼ 2:2844 and n e ¼ 2:1908 at 633 nm, respectively, which were close to those of 3 mol% MgO-doped stoichiometric LN.

Combinatorial High-Vacuum Chemical Vapor Deposition of Textured Hafnium-Doped Lithium Niobate Thin Films on Sapphire

“…In efforts toward deposition of doped-lithium niobate thin films, so far deposition of cobalt-doped lithium niobate films using combinatorial pulsed-laser deposition (PLD) 11 and deposition of magnesium-doped lithium niobate films using low-pressure (LP) CVD 12 have been reported. Here we report on deposition of textured {001} hafnium-doped lithium niobate (Hf:LiNbO 3 ) thin films on {001} sapphire substrates using a combinatorial HV-CVD process.…”