The dual electron emission spectromicroscope: a novel multi-technique instrument for surface analysis

The concept, design and performance of the novel dual emission electron spectromicroscope (DEEM) are presented. The DEEM consists of four fully electrostatic lens systems comprising two independent and parallel projective columns, objective lens system and deflector lens system. Switching on the deflector lens potentials causes a parallel shift of the electron beam from the axis of the of the first projective lens column to the axis of the second projective column. This original concept allows for the quasi-simultaneous observation of the complementary diffraction (angular distribution) and imaging planes at the two independent imaging units. The dispersive properties of the deflector lens system can also be used to select the energy range of the electrons emitted from the sample for analysis. Consequently, energetically and laterally resolved measurements are possible and a plurality of image contrast mechanisms are available.