Hot Electron Emission from Silicon Surfaces

The decrease of the emission efficiency of hot electrons from a reverse-biased silicon junction has been measured as a function of time after etching. The decrease is largely due to a change in the surface potential of the silicon emitter. A density of surface states of 8×1012/cm2 has been determined from the effective attenuation distance of the hot electrons in the growing surface oxide layer, and from the characteristic energy of the emitted electrons. Changes in emission efficiency due to interface and oxide layer scattering have been determined from the emission efficiency for the more energetic electrons. A linear growth rate of the surface oxide induced by continuous charging of the surface states has been found.