AVS 50th International Symposium
    Thin Films Wednesday Sessions
       Session TF-WeP

Paper TF-WeP11
Influence of the Microstructure on the Sputter-etching Characteristics of Pulsed-laser Deposited Strontium-titanate-oxide Thin Films

Wednesday, November 5, 2003, 11:00 am, Room Hall A-C

Session: Poster Session
Presenter: J. Margot, Universite de Montreal, Canada
Authors: L. Stafford, Universite de Montreal, Canada
M. Gaidi, INRS-Energie, Canada
O. Langlois, Universite de Montreal, Canada
M. Chaker, INRS-Energie, Canada
J. Margot, Universite de Montreal, Canada
M. Kulishov, Adtek Photomask Inc., Canada
Correspondent: Click to Email
Strontium-titanate-oxide (STO) thin films are of great interest for several photonic applications such as high-speed electro-optic elements for next-generation all-optical networks. Obviously, the integration of STO layers into such devices requires a simultaneous optimization of the deposition method and of the patterning process. In this context, we have investigated the influence of the deposition parameters on the etching characteristics. For this purpose, in a first step, stoichiometric SrTiO3 thin films with the crystallographic perovskite structure were grown on a silicon substrate using a Pulsed-Laser Deposition (PLD) technique. The microstructural properties of the films were studied as a function of the buffer gas pressure (O2). In a second step, we have examined the sputter-etching characteristics of the as-deposited films using a high-density argon plasma operated at very low pressure (1 mTorr) and a substrate bias of 100 V. The etch rate of the STO thin films is found to increase with the O2 deposition pressure, a feature that can be related to the microstructural properties of the film (grain size, lattice parameter, etc.) induced by changes in growth conditions. We will show that the etch rate is actually related to the macroscopic film density (film porosity) rather than to its microscopic density (unit cell volume of the film).