Bend-inducing internal stress determination in coated substrate - by surface curvature measurement using scanning probe of film thickness measuring device

摘要

Determination of bend-inducing mechanical stresses, caused by differential thermal expansion in a composite body comprising a substrate and one or more relatively thin layers, is carried out by measuring the composite body surface curvature as a measure of the stresses. The novelty comprises measuring the surface curvatures of the composite body (2) and the uncoated substrate (3) and subtracting the measured values, using a measuring process in which (a) the surfaces are scanned, according to a preset raster pattern, by the needle-like measuring probe (8) of a layer thickness measuring device (6); and (b) the composite body (2) and the uncoated substrate (3) are each placed on three support points (7a,b) of a holder (7). USE/ADVANTAGE - For determining mechanical stresses in a thin oxidic buffer layer or in a superconductor layer in the deposition of a high dc metal oxide superconductive material onto a substrate opt. covered with a buffer layer (claimed).