|AVS 55th International Symposium & Exhibition|
|Advanced Surface Engineering||Thursday Sessions|
|Session:||Advanced Surface Engineering Poster Session|
|Presenter:||M.V. Sopinskyy, V Lashkaryov Institute of Semiconductor Physics, NASU, Ukraine|
|Authors:||M.V. Sopinskyy, V Lashkaryov Institute of Semiconductor Physics, NASU, Ukraine
I.Z. Indutnyy, V Lashkaryov Institute of Semiconductor Physics, NASU, Ukraine
V.I. Mynko, V Lashkaryov Institute of Semiconductor Physics, NASU, Ukraine
P.E. Shepeliavyi, V Lashkaryov Institute of Semiconductor Physics, NASU, Ukraine
|Correspondent:||Click to Email|
Polarization conversion effect have been studied to find out anisotropy in the obliquely deposited SiOx and As2S3 films. The films were obtained by thermal evaporation and oblique deposition of SiO and As2S3 onto polished Si and silica substrates. During deposition the substrates were oriented at the angles β between the normal to the substrate surface and the direction to the evaporator. The polarization conversion is an interesting phenomenon which causes the fraction of p(s)-polarized light incident on an anisotropic thin film be reflected as s(p)-polarized light.1 The optical anisotropy of the obliquely deposited SiOx and As2S3 films was detected using the data on the polarization conversion of the electric vector caused by the passage of polarized light through the film. For this purpose the light beam with the electric vector linearly polarized in the direction perpendicular to the plane of incidence (the s-polarized light beam) was projected on the samples and the ellipsometer table was rotated around the normal to the sample surface (rotation angle α = 0°-360°). The angular rotation of analyzer (θ) was measured by means of the ellipsometer with a sensitivity of 0.02°. Normally deposited SiOx and As2S3 films don’t show any in-plane anisotropy. For As2S3 films deposited at β=75° and SiOx films deposited at β=60° there are observed θ(α) dependencies with the period of 180° (symmetrical, or assymetrical). In this case, principal axes of high-frequency dielectric constant tensor εik for those films are mutual perpendicular, and two of them lie in the plane parallel to film substrate (one is parallel, and another perpendicular to the direction of the projection of the vapor-beam’s direction on the substrate surface). The third principal axis of εik is perpendicular to the substrate surface or is slightly inclined to the perpendicular. For SiOx films deposited at β=75° θ(α)-dependencies have 360°period value. In this case the third principal axis of εik is inclined toward the substrate surface. It directly shows that obliquely inclined columns are formed in such films. Thus, investigation of polarization conversion effect is simple, nondestructive and useful method to distinguish the type of in-plane and out-of-plane structural anisotropy of obliquely deposited films.
1R. M. A. Azzam and N. M. Bashara, (1986). Ellipsometry and Polarized Light (Amsterdam: North-Holland).