Deposition of crystal polythiophene thin films by KrF excimer laser ablation

2000 ◽  
Vol 15 (2) ◽  
pp. 536-540 ◽  
Author(s):  
Y. F. Lu ◽  
Z. M. Ren ◽  
Z. H. Mai ◽  
T. C. Chong ◽  
S. C. Ng ◽  
...  

Thin films of polythiophene, a kind of polyheterocyclic compound with hydrogen function groups, were deposited by KrF excimer laser ablation of a compressed solid target in a vacuum chamber. The laser pulse fluence was approximately selected at 2 J/cm2 with a pulse duration of 25 ns. The structural, topographic, and electronic properties of the deposited thin films were analyzed by atomic force microscope, x-ray diffraction, and Raman and infrared spectroscopy measurements. Deposited thin films were observed to have good crystal properties and to be composed of crystalline cubes with a uniform size of 0.1 μm. The electronic structure of the deposited thin films should be different from the target materials, resulting from the laser irradiation effects. The influence of the deposition temperature on the structural and electronic properties of the deposited thin films was studied.

1998 ◽  
Vol 526 ◽  
Author(s):  
Kenji Ebihara ◽  
Hiromnitsu Kurogi ◽  
Yukihiko Yamagata ◽  
Tomoaki Ikegami ◽  
Alexander M. Grishin

AbstractThe perovskite oxide YBa2Cu3O7-x (YBCO) and Pb(ZrxTi1-x)O3 (PZT) thin films have been deposited for superconducting-ferroelectric devices. KrF excimer laser ablation technique was used at the deposition conditions of 200-600mTorr O2, 2-3J/cm2 and 5-10 Hz operation frequency. Heterostructures of PZT-YBCO-YAlO3:Nd show the zero resistivity critical temperature of 82K and excellent ferroelectric properties of remnant polarization 32 μC/cm2, coercive force of 80kV/cm and dielectric constant 800. Cycling fatigue characteristics and leakage current are also discussed.


1996 ◽  
Vol 433 ◽  
Author(s):  
Hiromitsu Kurogi ◽  
Yukihiko Yamagata ◽  
Tomoaki Ikegami ◽  
Kenji Ebihara ◽  
Bok Yin Tong

AbstractPb(ZrxTi1−x)O3(PZT) thin films have excellent ferroelectric, optical, piezoelectric and pyroelectric properties. We prepared PZT thin films using the excimer laser ablation technique. A pulsed KrF excimer laser was used to ablate PZT bulk targets. We have studied optimum preparation conditions such as an oxygen pressure, a laser energy fluence and a substrate temperature.In this paper, we investigated the composition, crystallization and ferroelectric properties of the PZT films prepared under various deposition conditions.The X-ray diffraction (XRD) patterns showed that the PZT films prepared on MgO(100) substrates at 600°C and with a laser fluence of 2J/cm2 had a perovskite - pyrochlore mixed structure. The condition of 100 mTorr oxygen pressure provided high quality perovskite films. It is found that the stoichiometric composition of the deposited films is obtained in ambient oxygen of 100˜400 mTorr. The ferroelectric properties of the Pt/PZT/Pt/MgO structure were studied. The capacitance-voltage characteristics and the corresponding hysteresis loop of the dielectric-electric field curve were discussed.We also studied optical emission of the PZT plasma plume to understand quantitative relation between the PZT film quality and the ablation plume plasma. We identified spectral lines originated in Pb, Pb+, Zr, Zr+, Ti, Ti+, PbO and TiO. These spectral intensities have remarkable dependence on the ambient O2 pressure.


1998 ◽  
Vol 84 (5) ◽  
pp. 2909-2912 ◽  
Author(s):  
Y. F. Lu ◽  
Z. M. Ren ◽  
W. D. Song ◽  
D. S. H. Chan ◽  
T. S. Low ◽  
...  

1998 ◽  
Vol 526 ◽  
Author(s):  
Ashok Kumar ◽  
M.R. Alam

AbstractPb(ZrxTi1-x)O3 (lead zirconate titanate or PZT) ferroelectric thin film capacitors are of considerable interest for the realization of memory devices such as nonvolatile random access memories (NVRAMs). The PZT capacitors were prepared on platinized silicon Pt/(100)Si using conducting oxide LaxSr1-xCoO3 (lanthanum strontium cobalt oxide or LSCO) as electrodes. The PZT and LSCO thin films were deposited by the KrF excimer laser ablation technique. The optimum preparation conditions such as oxygen pressure, laser energy influence and substrate temperature were investigated. The PZT and LSCO films grown on Pt/(100)Si are polycrystalline. The crystallographic properties of the films were determined using X-ray diffractometer (XRD) method. The electrical characterizations of the films including hysteresis loop, fatigue, and retention properties were determined by the RT66A Standardized Ferroelectric Test System.


1990 ◽  
Vol 191 ◽  
Author(s):  
Michael E. Geusic ◽  
Alan F. Stewart ◽  
Larry R. Pederson ◽  
William J. Weber ◽  
Kenneth R. Marken ◽  
...  

ABSTRACTExcimer laser ablation with an in situ heat treatment was used to prepare high quality superconducting YBa2Cu3O7−x thin films on (100)-SrTiO3 and (100)-LaAlO3 substrates. A pulsed excimer laser (XeCl; 308 nm) was used to ablate a rotating, bulk YBa2Cu3O7−x target at a laser energy density of 2–3 J/cm2. Based on four-probe dc resistance measurements, the films exhibited superconducting transition temperatures (Tc, midpoint) of 88 and 87K with 2K (90–10%) transition widths for SrTiO3 and LaAlO3, respectively. Transport critical current densities (Jc) measured at 77K were 2 × 106 and 1 × 106 A/cm2 in zero field for SrTiO3 and LaAlO3, respectively. X-ray diffraction (XRD) analysis showed the films to be highly oriented, with the c-axis perpendicular to the substrate surface.


2000 ◽  
Vol 114 (11) ◽  
pp. 585-588 ◽  
Author(s):  
S Bhattacharyya ◽  
S.S.N Bharadwaja ◽  
S.B Krupanidhi

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