Jyrki Lappalainen

Education:
M. Sc. (Electrical Engineering), 1993
D. Sc. (Microelectronics), 2000

Address:
Microelectronics and Materials Physics Laboratories,
University of Oulu
P.O. Box 4500
FIN-90014 UNIVERSITY OF OULU
FINLAND

 
Home Address:
Toivoniementie 13 As. 27, 90500, OULU, FINLAND

 
Phone:
+358-(0)8-5532720 (work)
+358-(0)500-848658 (mobile)

 
Email:
jyla@ee.oulu.fi

 
Fax:
+358-(0)8-5532728

Research interests:
 
• Pulsed laser deposition (PLD) of the ferroelectric lead-zirconate-titanate (PZT) thin films. Characterization of
the laser-ablation process and thin-film growth mechanisms in order to optimize the film growth parameters and conditions.
The formation of particulates and the changes in the target surface structure and chemical composition due to the laser
heating during the PLD process.
 
• Dielectric and polarization properties of the post-annealed PZT thin-film capacitor structures with platinum electrodes also
deposited by PLD process. Electrical conductivity of the PZT films with high dc resistivity values. Determination of the
state of macroscopical stress in the PZT films and the dependence of the electrical properties on the stress state of the film.
 
• PLD growth of the multilayer thin film structures of PZT and various electrode materials on MgO, sapphire and silicon
substrates in order to study the properties of these component prototypes in the FERAM, piezoelectric micromovement
actuator (bimorph), pyroelectric sensor and electro-optic waveguiding applications.

 
• Optical characterization of the PLD-growth post-annealed PZT thin films at the visible wavelengths (about 250-800 nm).

Determination of the optical constants and the energy gap of the polycrystalline films. Dependence of the optical characteristics
of PZT films on deposition and post-annealing parameters.
 

Latest publications:

• J. Lappalainen et al., Excimer Laser Ablation of PZT Thin Films on Silicon Cantilever Beams,
Sensors and Actuators A, 46-47 (1995) 104-109.
 
• J. Frantti, V. Lantto and J. Lappalainen, Symmetry Considerations of Raman Modes in Nd-doped PZT Thin Films for
Structure Characterization, Journal of Applied Physics, 79 (1996) 1065-1072.
 
• J. Frantti, V. Lantto and J. Lappalainen, Group-Theoretical Consideration of Raman Modes in Nd-doped PZT Thin Films
for Structure Characterization, Ferroelectrics, 184 (1996) 69-78.
 
• J. Lappalainen, J. Frantti and V. Lantto, Electrical and Mechanical Properties of Ferroelectric Thin Films Laser Ablated from
a Pb_0.97Nd_0.02(Zr_0.55Ti_0.45)O₃ Target, Journal of Applied Physics, 82 (1997) 3469-3477.
 
• J. Lappalainen and V. Lantto, Extrinsic Conductivity in Ferroelectric PZT Film Capacitors Made by Laser Ablation Deposition,
Physica Scripta, T79 (1999) 220-224.
 
• J. Lappalainen, J. Frantti and V. Lantto, Surface Structure and Particulate Generation in Pb_0.97Nd_0.02(Zr_0.55Ti_0.45)O₃ Ablation
Targets During Pulsed Laser Ablation, Journal of the American Ceramic Society, 82 (1999) 889-896.
 
• J. Lappalainen, J. Frantti and V. Lantto, Effect of Laser-Ablation Process Parameters and Post-Annealing Treatment on
Ferroelectric PZT Thin Films, Applied Surface Science, 142 (1999) 407-412.

 
• J. Lappalainen and V. Lantto, Composition and Phase Structure in Laser-deposited and Post-annealed  Pb_1-3y/2Nd_y(Zr_xTi_1-x)O₃

Thin Films,  Applied Surface Science, 154-155 (1999) 118-122.


• J. Lappalainen, V. Lantto, J. Frantti and S. A. Ivanov, Optical Properties and Surface Morphology of Pulsed-Laser-Deposited

Polycrystalline PNZT Thin Films, Journal of the European Ceramic Society, in press (2000).
 

Last update: 27.10.2000