ENERGY-LOSS AND ESCAPE DEPTH OF HOT-ELECTRONS FROM SHALLOW P-N-JUNCTIONS IN SILICON

The emission of electrons from a reverse-biassed p-n located below and parallel to an n-type emitting surface has been investigated experimentally. By sputter thinning the n layer, followed by annealing and CS-O treatments all in vacuum, we have been able to measure the energy distributions of emitted electrons at several different n-layer thicknesses, allowing direct application of a theoretical treatment due to Baraff. The surface barrier of ∼1.1 eV enables us to sample electrons having an average energy of about 3.0 eV above the conduction-band minimum. At these energies, considerably below those studied by most others, we find the mean free path for optical phonon emission, L p, to be 141 Å, for ionization, Li, to be 8526 Å, and the total attenuation length, Lo, to be 359 Å.