J. Eisenmenger et al., Nondestructive magneto-optical characterization of natural and artificial defects on 3 '' HTSC wafers at liquid nitrogen temperature, IEEE APPL S, 9(2), 1999, pp. 1840-1843
Double-sided 3 " HTSC Wafers were characterized by the magneto-optic techni
que. The presented apparatus allows a nondestructive and fast detection of
local and extended inhomogeneities in the critical current density with hig
h lateral resolution in the micrometer range. Additional gold-layers on the
HTSC wafers, as they are sometimes used for the device production, do not
influence the characterization result. The high sensitivity of the presente
d apparatus allows even the detection of local defects at higher temperatur
e (77 K) where contrasts in the critical current are weaker and the magneto
-optical characterization of HTSC thin films is much more difficult than at
lower temperatures. So the apparatus can be used even under conditions whe
re cooling with liquid helium or closed-cycle refrigerators is not availabl
e. The sensitivity was tested on natural and artificial defects, the latter
being prepared by means of a focused laser beam.