Sputtered Ferroelectric Thin Films of KTN for Electro-Optic Devices

摘要

Major accomplishments of this program are the demonstrations summarized below:(1) Large grain (0.5 to 0.8 micrometer), high preferred orientation (100) films of Pt on SiO2/Si substrates by use of high deposition temperatures (600-650 deg C) with a trace of reactive O2 gas in the rf-PM sputtering gas. The Pt film, besides functioning as metallization for bottom electrodes for capacitors, promotes epitaxial like growth within its large grains and high crystal quality of the overlying KTN film. (2) Epitaxial growth of KTN films on GaAs (100) and 'r' plane' (1012) Sapphire substrates with film normal along < 100 > polar direction. (3) First time observation of Ferroelectric Curie-Weiss behavior of KTN films by rf-PM sputtering on GaAs and Pt/SiO2/Si substrates with peak dielectric constants of nearly 2250 (at 1 KHz); Sharp Curie transition temperatures (-9 to +3 deg c) with bulk single crystal like characteristics. (4) High optical transmittivity of KTN films on Sapphire with nearly 99.5% of theoretical transmittivity. (5) High quadratic EO effect in paraelectric phase of KTN films on GaAs and Si substrates. Observed EO effect is nearly 70% larger than for the same effect in PLZT thin films in ferroelectric phase.... Ferroelectric thin films, Electro-optic devices, Thin films, Platinum films, Sapphire.