Development of a projection imaging electron microscope with electrostaticlenses

In the semiconductor industry, the inspection technique using an electron b eam is expected to play an important role because of its high spatial resol ution. In comparison with conventional scanning techniques, direct imaging produced by projection optics offers both faster mapping rates due to paral lel detection and higher resolution. An electron microscope based on the pr ojection imaging optics has been designed and constructed. Secondary electr ons emitted by the area exposure are projected through the projection optic s consisting of fully electrostatic lenses, and then imaged onto the image detection system. A computational analysis indicates resolution of 0.27 mu m which can satisfy both adequate resolution and image grab time. An image of a 0.2 mu m design rule device is demonstrated. (C) 1999 American Vacuum Society. [S0734-211X(99)05706-6].