SEM cathodoluminescence (CL) is extended to luminescence center spatia
l depth profiling by means of electron beam energy E-o variation and c
onsequently variation of CL excitation range. In this way the CL profi
le of SiO2-layers on Si substrate offers a dead layer of luminescence
beneath the surface (10-75) nm as well as the SiO2 oxide thickness wit
h an accuracy of better 10% across a small spot area of less than 1 mu
m.