Focusing properties of micron-sized immersion lenses

We report here on the focusing properties of a two-electrode electrostatic immersion lens of micron dimensions that is combined with the electron point source. Depending on the mode of operation of the lens, the resulting focused electron beam can have an energy as low as 15 eV if the lens is used in the decelerating mode, or an energy of typically 200 eV if the lens is used in the accelerating mode. We will also present results of using the focused beam in a TEM setup as well as in the scanning mode. © 1996 American Institute of Physics.