Apparatus and method of pattern detection based on a scanning transmission electron microscope

A scanning electron microscope with a sharply converged electron beam operating to scan a sample and detect reflected electrons, secondary electrons or transmitted electrons by an image detection system to provide an electron image signal y(t), wherein said microscope comprises:

• noise elimination means for eliminating a noise in the electron image signal y(t) detected by said image detection system by smooth-processing in a nonlinear fashion the electron image signal y(t);
• restoration means for obtaining a restoration waveform image signal x(t) by processing said noise eliminated electron image signal y(t) in accordance with an equation h(t) process resulting from an inverse Laplace transformation for an inverse function H(s) of a transfer function G(s) which approximated the response delay characteristics of said image detection system so as to recover the deterioration of the detected image signal y(t) provided by the image detection system;
• and,
• means for recognizing the pattern of the sample by the restoration waveform image signal x(t).

A scanning electron microscope with a sharply converged electron beam operating to scan a sample and detect reflected electrons, secondary electrons or transmitted electrons by an image detection system to provide an electron image signal y(t), wherein said microscope comprises:

• restoration means for obtaining a restoration waveform image signal x(t) by processing said electron image signal y(t) in accordance with an equation h(t) process resulting from the inverse Laplace transformation for an inverse function H(s) of a transfer function G(s) which approximated appropriately the response delay characteristics of said image detection system so as to recover the deterioration of the detected image signal y(t) provided by the image detection system;
• means for obtaining an ideal image signal from design data;
• and,
• means for recognizing the pattern of the sample by comparing the restoration waveform image signal x(t) with an ideal image signal obtained from said obtained mean.

A scanning electron microscope operating to scan a sample with a sharply converged electron beam and detect reflected electrons, secondary electrons or transmitted electrons by an image detection system to provide an electron image signal y(t), wherein said microscope comprises:

• means for obtaining an ideal image signal from design data;
• means for adding a transfer function G(s) which approximated appropriately the response delay characteristics of said image detection system, to said ideal image signal so as to recover the deterioration of the detected image signal y(t) provided by the image detection system;
• and,
• means for recognizing the pattern of the sample by comparing the electron image signal y(t) with said response delay ideal image signal obtained from said adding means.