Properties of lithium niobate thin films by RF magnetron sputtering with wafer target

Abstract

Use of a rapid thermal annealing technique is shown to improve the electrical and structural properties of LiNbO3/Si (100) structures. The lithium niobate film was deposited in an RF magnetron sputtering system with wafer-type of LiNbO3 target added Li2O at a substrate temperature of below 300 degrees C. A post-deposition annealing was conducted for 60 seconds at 600 degrees C. The rapid thermal annealed films were changed to polycrystalline ferroelectric nature from amorphous of as-deposition. The resistivity of the ferroelectric LiNbO3 film increased from a typical value of 1 similar to 2 x10(8) Omega.cm before the annealing to about 1x10(13) Omega.cm at 500 kV/cm and reduced the interface state density of the LiNbO3/Si(100) interface to about 1x10(11)/cm(2).eV. Ferroelectric hysteresis measurements using a Sawyer-Tower circuit yielded remanent polarization and coercive field values of about 1.2 mu C/cm(2) and 120 kV/cm, respectively.