Measurements of linear dimensions of silicon nanorelief elements with a near-rectangular profile by defocusing the electron probe of a scanning electron microscope

Solitary silicon nanorelief elements with different widths are studied with the use of a scanning electron microscope (SEM). From the video signal curves obtained in the secondary-slow-electron mode of SEM measurements, the dependences of the length of check segments G p (D ef) and L p (D ef), where D ef is the effective diameters of the SEM probe, are determined. The dependences are found to be linear for all four solitary protrusions, and as D ef is increased, the length G p increases and the length L p decreases. It is shown that the method of defocusing the SEM electron probe provides a means for determining the linear dimension of nanorelief elements with a near-rectangular profile by extrapolating the linear dependences G p (D ef) and L p (D ef) to D ef = 0. It is established that the invariant check segment representative of the linear dimension of a particular relief element is at the level (sl)aver = 0.80 ± 0.03 for silicon elements with different widths.