Abstract
Highly (111) oriented, phase-pure perovskite Pb(Zr0.3Ti 0.7)O3 (or PZT 30/70) thin films were deposited on single-crystal, (0001) wurtzite GaN/sapphire substrates using the sol-gel process and rapid thermal annealing. The phase, crystallinity, and stoichiometry of annealed PZT films were evaluated by X-ray diffraction and Rutherford backscattering spectroscopy. The atomic force microscopy revealed a smooth PZT surface (rms roughness 1.5 nm) with striations and undulations possibly influenced by the nature of the underlying GaN surface. The cross-sectional field-emission scanning electron microscopic images indicated a sharper PZT/GaN interface compared to that of sol-gel derived PZT on (111) Pt/TiO 2/SiO2/(100) Si substrates. The capacitance-voltage (C-V) characteristics for PZT in the Pt/PZT/GaN (metal-ferroelectric-semiconductor or MFS) configuration were evaluated as a function of annealing temperature and applied voltage. The observed C-V hysteresis stemmed from trapped charge at defect sites within PZT. Also, the lower capacitance density (C/A = 0.35 μF/cm2, where A is the area of an electrode) and remnant polarization (P r 4 μC/cm2) for PZT in the MFS configuration, compared to the values for PZT in the MFM configuration (Pt/PZT/Pt), were attributed to the high depolarization field within PZT.
Original language | English (US) |
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Pages (from-to) | 389-395 |
Number of pages | 7 |
Journal | Journal of Sol-Gel Science and Technology |
Volume | 42 |
Issue number | 3 |
DOIs | |
State | Published - Jun 2007 |
Keywords
- Ferroelectric
- GaN
- Pb(ZrTi)O
- Sol-gel
- Thin film
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Ceramics and Composites
- General Chemistry
- Biomaterials
- Condensed Matter Physics
- Materials Chemistry