3-D mapping with ellipsometrically determined physical thickness/refractive index of spin coated sol-gel silica layer

Precursor sol for sol-gel silica layer was prepared from the starting material, tetraethylorthosilicate (TEOS). The sol was deposited onto borosilicate crown (BSC) glass by the spinning technique (rpm 2500). The gel layer thus formed transformed to oxide layer on heating to 450degreesC for similar to30 min. The physical thickness and the refractive index of the layer were measured ellipsometrically (Rudolph Auto EL 11) at 632.8 nm. About 10 x 10 mm surface area of the silica layer was chosen for evaluation of thickness and refractive index values at different points (121 nos.) with 1 min gap between two points. Those data were utilized in the Auto-lisp programme for 3-D mapping. Radial distribution of the evaluated values was also displayed.