Experimental studies of the electron ray defocusing method in nanosize objects geometric parameters measurements in the low voltage mode of a scanning electron microscope

We measure the linear sizes of a nanorelief element with trapezoid profile using a scanning electron microscope (SEM) working at accelerating voltage 800 V by the electron ray defocusing method. It is shown that a signal in the secondary electrons can be represented as a piecewise linear function with characteristic break points. It is found that the distance between the extrema and points of the beginning of signal increase depends linearly on the effective diameter, a SEM electron ray. The extrapolation of the straight lines on =0 allows us to determine the values of the sizes of the upper and lower bases of the above nanorelief element and the mean value of the projection of the side wall of the element.