Determination of the electron mean free path in the 1-1.8 eV energy range in thin gold layers using ballistic electron emission microscopy
Résumé
Electron mean free path (λa) has been investigated using Ballistic Electron Emission Microscopy (BEEM). Using the average collector current computed from large scale BEEM images and a model in which the current exponentially decreases in terms of metal thickness, a constant value of λa = 11 nm has been calculated in the 1-1.8 eV electron energy range. On small scale images, the study of well-defined BEEM domains shows that either λa or the interface transmission factor (or both) may differ from their average values. These local variations from one grain to another are interpreted as interface defects and channeling of the electron beam due to the electronic and crystallographic of the gold layer.