Messung der Eindringtiefe von Elektronen und Ionen in dünnen Aufdampfschichten

Abstract

The penetration depth of electrons, H⁺-, He⁺-, Ne⁺-, and Ar⁺-ions in thin evaporated layers of alkali fluorides and alkaline earth fluorides has been investigated by measuring the excitation and deterioration of the luminescence caused by the bombardement with electrons and ions. Particle energy ranged up to 10 keV for electrons and the lighter ions and up to 30keV for the heavier ions; film thicknesses were chosen between 5 and 100μg/cm². The penetration depths defined by the two different techniques are called “maximum excitation depth” and “maximum deterioration depth”. By measuring the excitation depth a depth distribution may be obtained. Using the Bethe-equation a numerical penetration depth-energy-relation for electrons was derived which gives good agreement with the experimental values. The results of the deterioration depths of the ions are compared with the theoretical predictions ofLindhard andScharff.