EFFICIENCY OF SI L-2,L-3 X-RAY GENERATION IN THE SIO2 SI SYSTEM BY ELECTRON-IMPACT/

The paper reports a study of the depth profile of the generation effic iency and escape of the ultrasoft silicon L-2,L-3 x-ray radiation exci ted by electrons of various energies. The generation function describi ng the excitation efficiency is the kernel of an integral equation det ermining the dependence of x-ray emission intensity on primary-electro n energy. To determine the form of this function, a study was made of the dependence of the Si L-2,L-3 x-ray spectral intensity and of its s ilicon L-2,L-3 component bands, from crystalline silicon and amorphous dioxide SiO2 on primary- electron energy in samples made from dioxide layers of various thicknesses grown on crystalline silicon. These exp eriments permitted investigation of the generation-function cross sect ions at the depth of the Si-SiO2 interface. The theoretical simulation of the generation function made use of the simplest laws governing el ectron interaction with solids and of the cross section of the inner-l evel ionization by electron impact in its most general form. A compari son of the experimentally obtained relative contributions of the Si an d SiO2 emissions with the calculations shows them to be in good agreem ent up to primary-electron energies of 2-3 keV. (C) 1998 American Inst itute of Physics. [S1063-7834(98)03410-8].