Electron energy loss in thin metallic films

Schottky diodes with patterned overlayers of thin metal films have provided a method to measure the energy loss of high energy electrons in the metal films. The technique avoids the problems of surface contamination and electron collection which complicate measurements on freestanding films. The patterned overlayer creates a modulation in the reverse biased diode current as a beam of focused electrons is moved across the diode surface. The amplitude of the modulation has been measured with overlayers of aluminum and gold for incident electron energies of 5 to 30 keV. The results have been compared to that predicted from a Monte Carlo calculation of the inelastic and elastic scattering of the incident electrons. Significantly better agreement between experiment and simulation is observed when the screened Rutherford cross section in the Monte Carlo code is replaced by an empirical expression for the Mott scattering formula. (C) 1996 American Institute of Physics.