Rectification Properties of Metal-Silicon Contacts

Abstract

Area contacts of twenty different metals were made on n and p silicon. The contacts were applied by the use of jet plating techniques, with the exception of alkali metal contacts which were pressure contact or mercury amalgam contact. A qualitative correlation is shown to exist between the work function of the metals and the rectification of these metals on n and p silicon. I–V characteristics taken on eleven of these metal‐silicon contacts lend further support to this picture. Consideration of a quantitative work function model is made difficult due to the many errors and interpretations involved in using metal work function values. Transistor structures were made and studied for several of the metal‐silicon contacts. From analysis of this transistor data it is found that an excess current three orders of magnitude greater than theory predicts, must be present in the diodes made from these metals. This excess current is not adequately explained by any presently known mechanism.