Growth, modeling and device implementation of pulsed laser-deposited thin films
General Material Designation
[Thesis]
First Statement of Responsibility
M. H. Rahman
Subsequent Statement of Responsibility
A. Kumar
.PUBLICATION, DISTRIBUTION, ETC
Name of Publisher, Distributor, etc.
University of South Alabama
Date of Publication, Distribution, etc.
1998
PHYSICAL DESCRIPTION
Specific Material Designation and Extent of Item
149
DISSERTATION (THESIS) NOTE
Dissertation or thesis details and type of degree
M.S.E.E.
Body granting the degree
University of South Alabama
Text preceding or following the note
1998
SUMMARY OR ABSTRACT
Text of Note
The purpose of this research investigation is to fabricate the ferroelectric thin film capacitors by laser ablation and Sol-Gel methods. Barium strontium titanate (Ba{0.5}Sr{0.5}TiO3), lead zirconium titanate (Pb{0.5}Zr{0.5}Ti{0.48}O3), and strontium bismuth tantalate (SrBi2Ta2O9) have been used as ferroelectric materials, and strontium ruthenium oxide (SrRuO3) has been used as top and bottom electrodes. The conducting electrode, strontium ruthenium oxide (SrRuO3), has been chosen as electrode material because of its chemical and mechanical stability and very smooth interface with ferroelectric material. The PZT, SBT, and BST-based capacitors were deposited on different substrates, such as MgO(200), Pt/(100)Si, and r-sapphire. The structural characterizations of the capacitors were examined by x-ray diffraction technique. The electrical characterizations of the capacitors were assessed by the RT66A Standardized Ferroelectric Test System. The PZT capacitors proved to be very reliable in terms of not losing much switched charge after a large number of repetitive polarization reversals (10 cycles) and being able to maintain their charge over long waiting periods (10 seconds) between a write and subsequent read pulse. On the other hand, SBT capacitors have been found to have better long-term properties than PZT capacitors. The BST-based capacitors show reasonable dielectric constants and, thus, have been proven to be very reliable memory devices. The Sol-Gel process has also been used to fabricate PZT capacitors, and the results have been compared to the capacitors made by the PLD method. The capacitors made by Sol-Gel process showed better long-term properties than those made by the PLD process.