Electrical Defects in Silicon Introduced by Sputtering and Sputter‐Etching
Abstract
Sputtering a gold contact on n‐silicon or sputter‐etching the silicon surface prior to deposition of gold results in a Schottky barrier which shows a barrier height which depends on the sputtering voltage and time, and is lower than a corresponding barrier obtained by evaporation of a gold contact. On p‐silicon a sputtered gold contact also shows a barrier height influenced by the sputtering conditions. The modifications of the barrier height are caused by a thin positively charged layer formed in the semiconductor near the metal‐semiconductor junction. During sputter etching the silicon surface is subject to bombardment by Ar ions with energies of about the sputtering voltage. If this voltage is high enough charged centers will be introduced. These centers are also observed after sputter deposition at high voltage. We found that damage is caused by etching at 500V but not at 100V. This indicates that the damage found after sputter deposition was caused by rebounded Ar atoms.