The role of hydrogen in altering the electrical properties of gold, titanium, and tungsten films

Abstract

Hydrogen was found to alter the electrical properties of gold (Au), titanium (Ti), and tungsten (W) thin films deposited on SiO2/Si substrates. Specifically, the addition of H2 was found to reduce both hillock growth and the rate of electromigration in Au and Ti films. The resistance and 1/f noise of unpassivated Au, Ti, and W films was also found to decrease in H2. The influence of H2 adsorption, absorption, compound formation, and film crystal structure [Au (fcc), Ti (hcp), and W (bcc)] on the rate of electromigration is explored. The data suggest that a modification of the stress state at the metal film/substrate interface is responsible for the decreased resistance, 1/f noise, and electromigration rates observed in H2.