Theory of ballistic electron emission microscopy - art. no. 125408

A theory of ballistic electron emission microscopy is presented that incorp orates constant-tunnel-current feedback and models the band-structure and s pace-charge effects on the electron transmission. The computation is beyond the effective-mass approximation but short of being from first principles. The transmission coefficient includes detailed symmetry treatments of the Gamma-, L-, and X-point semiconductor conduction channels and the three-dim ensional k-space current injection dependency. This approach naturally lead s to the inclusion of multiple current channels, i.e., simultaneous inclusi on of several propagating and evanescent bands of various symmetry types. W e investigate the effects of the model parameters on the I-V spectra and co mpare our predictions to experiment, yielding fairly good agreement. We als o compare theoretical and experimental Au/GaAs(001) dI/dV data and find tha t the L point does not contribute to an observable threshold and that the c orresponding experimental feature is due instead to band-structure effects.