FIELD: measuring equipment.
SUBSTANCE: invention relates to interoperative monitoring of mechanical stress and defects in functional layers. The method includes ellipsometric measurements of refraction index in local areas of film. The method also presupposes that one should determine film thickness dƒ and the refraction indices for the ordinary ray no and the extraordinary ray ne in each area of film. The rays are used to calculate the values of birefringence Δn: Δn=(no-ne). The map of mechanical stress and the defects caused by it is determined according to the law of photoelasticity: σ=Δn/k where k is the elastic-optical constant determined by the formula: k=Δn/σ, with the use of the value determined by the Stony formula: where ds, ν and Es denote thickness, Poisson's ratio and Young's modulus of the substrate, R is the effective radius of curvature of the substrate with film. Topographic relief (or, in other words, local radii of curvature of the surface) is determined by the value of birefringence Δn and layer thickness dƒ.
EFFECT: invention reduces time and complexity of monitoring defectiveness and mechanical stress and expands the range of measured parameters.
1 cl, 1 tbl, 2 dwg
Authors
Dates
2021-03-16—Published
2020-06-25—Filed