High Resolution X-Ray Elemental Mapping Using 300-kV Field-Emission TEM

A high-resolution X-ray elemental mapping system has been developed for use with a 300-kV Reid-emission TEM. The optimum illuminating condition for elemental mapping is estimated by calculation of the electron optic characteristics where a spot size of 0.5 nm or less for probe currents between 0.07 nA and 0.7 nA is obtained. This condition is applied for elemental mapping of an InP/InGaAs superlattice. The layers with 1.2 nm to 9.7 nm thickness are clearly observed and a 0.6-nm layer is indistinctly observed. Thus, it is confirmed that the X-ray elemental mapping with high-resolution is successfully attained.