טכניון מכון טכנולוגי לישראל
הטכניון מכון טכנולוגי לישראל - בית הספר ללימודי מוסמכים  
M.Sc Thesis
M.Sc StudentDrezner Haika
SubjectElectro-Optical PLZT Thin Films Deposited on Silicon
Substrates
DepartmentDepartment of Materials Science and Engineering
Supervisor Professor Berger Shlomo


Abstract

The main goal of our research is to study thin PLZT films as a solution of polarization correction in the device. This goal requires in depth study of fabrication method and characterization of microstructure, composition, dielectric and electro-optic properties of the film.

In our research, the films were manufactured by a "wet" method called "Polymeric precursor method" and a "dry" method- using a pulse laser deposition (PLD) system from a PLZT 9/65/35 commercial target.

 Preparing PLZT thin films by a "wet" method does not require expensive and sophisticate equipment, and allows good composition control.

The research presents an optimization of the "wet" process parameters throughout the different steps and their influence on the quality of the deposited films. 

The films morphology and thickness were characterized using HRSEM. The composition of the PLZT powder and the deposited films was characterized using EDS. PLZT thin films prepared by the "wet" process were characterized using XRD. The maximum thickness of the PLZT films achieved by this method is about 170nm, after 15 deposition cycles. The XRD diffraction pattern showed the presence of pyrochloric phase in addition to the perovskite phase. In order to stabilize the perovskite phase, an access of PbO was needed to the initial powder.

In order to check the possibility of rotating the light polarization, 1mm thick PLZT films were deposited on a commercial die (Lambda crossing LTD) using the PLD technique. The quadratic electro-optic coefficient was measured and found to be R=1.96x10-16 m2/V2, which is lower by a factor of about 4 compared to reported values of a single crystal PLZT in the literature and comparable to reported values of thin PLZT films.