AVS 47th International Symposium
    Thin Films Thursday Sessions
       Session TF-ThM

Paper TF-ThM2
Structural Characterization of High and Low Index PECVD Optical Coating Materials: The Case of Titanium Dioxide and Silicon Dioxide

Thursday, October 5, 2000, 8:40 am, Room 203

Session: Optical Films
Presenter: V. Hajek, Ecole Polytechnique, Canada
Authors: V. Hajek, Ecole Polytechnique, Canada
M. Latreche, Ecole Polytechnique, Canada
J.E. Klemberg-Sapieha, Ecole Polytechnique, Canada
L. Martinu, Ecole Polytechnique, Canada
A. Argoitia, Optical Coating Laboratory Inc.
W.T. Beauchamp, Optical Coating Laboratory Inc.
Correspondent: Click to Email
In the present work we systematically study the optical, mechanical and structural characteristics of high index TiO@sub2@ and low index SiO@sub2@ films prepared by plasma enhanced chemical vapor deposition (PECVD) under controlled ion bombardment conditions. The films were obtained either individually from titanium tetrachloride (TiCl@sub4@), hexamethyldisiloxane (HMDSO), silicon tetrachloride (SiCl@sub4@) or from TiCl@sub4@/SiCl@sub4@ or TiCl@sub4@/HMDSO mixtures. Depositions were performed using radiofrequency (13.56 MHz) or dual-mode microwave/radiofrequency low pressure plasma systems; the latter one allows for a selective control of the ion energy and ion flux. In the first series of experiments we show that depending on the substrate bias voltage and temperature the refractive index for TiO@sub2@ at 550 nm varies from 2.20 to 2.40, the extinction coefficient remains low (k ~ 1-5 x 10@super-5@), and the film microhardness of about 10 GPa and low stress (0 - 200 MPa in compression) point to good film mechanical integrity. In the second series of experiments we study the transition from amorphous to crystalline structure, chemical bonding, and the role of chlorine in TiO@sub2@, SiO@sub2@ and mixed TiO@sub2@/SiO@sub2@ systems using ERD, XRD, FTIR, microraman, SEM and TEM techniques. The evolution of the microstructure is related to the energetic conditions during the film growth.