Patent ID: 7432503
Filing Date: 2008-10-07
Classification: G01N,H01J

Abstract:
1. A scanning electron microscope comprising: an electron beam source for emitting an electron beam; an electron beam converging means for converging said electron beam on an observation target surface; a beam current control means for controlling a beam current of said electron beam; an electron beam scanning means for making said electron beam being scanned on said observation target surface; a scanning position correction means for controlling a scanning position of said electron beam scanning means; an observation target moving means for moving said observation target so that said observation target surface is within a scanning range of said electron beam by said electron beam scanning means; an electron detector for detecting a secondary electron or a reflected electron generated by scanning said electron beam on said observation target surface; an image formation means for forming an image based on a detection value of said electron detector; a signal gain adjusting means for adjusting a corresponding relation between the secondary electron or reflected electron detected by said electron detector and said image formation means; a control amount memory means for saving in advance an adjustment amount of said signal gain adjusting means so that the detection value of said electron detector falls within a predetermined range in setting a plurality of beam currents or for saving a calculation algorithm of the adjustment amount; and an image detecting condition control means for changing an image detecting condition in accordance with a change in the beam current by using said adjustment amount or said calculation algorithm obtaining for the adjustment amount, which is saved in said control amount memory means.