Multiferroic Bi(0.7)Dy(0.3)FeO(3) thin films directly integrated on Si for integrated circuit compatible devices

Magnetoelectric multiferroic Bi(0.7)Dy(0.3)FeO(3) (BDFO) thin films deposited on p-type Si (100) substrate using pulsed laser deposition technique demonstrated a saturated ferroelectric and ferromagnetic hysteresis loop at room temperature. More interestingly, the observed change in electric polarization with applied magnetic field in these films indicated the presence of room temperature magnetoelectric coupling behavior. Using high-frequency capacitance-voltage measurements, the fixed oxide charge density, interface trap density and dielectric constant were estimated on Au/BDFO/Si capacitors. These results suggest the integrated circuit compatible application potential of BDFO films in the field of micro-electro-mechanical systems and nonvolatile memories.

Aqueous sol-derived ferroelectric thin films of PbTiO3 directly on Si(100) substrate

Ferroelectric thin films of PbTiO3 are prepared directly on Si(100) substrate for the first time by spin coating an aqueous sol of lead and titanium hydroxy complex and post annealing at various temperatures. The X-ray diffraction patterns show that the films are polycrystalline in nature. Scanning electron microscopy reveals that the films 0.3 mu m in thickness are essentially crack-free. Since there is no organic content in the precursor solution, post deposition shrinkage is reduced. This helps to decrease the possibility of film cracking. The ferroelectric properties of the films are comparable to those obtained by the complex alkoxide route and other expensive techniques. Copyright (C) 1997