ROLE OF ENERGETIC ATOMS AND IONS IN TA FILMS GROWN BY DIFFERENT PHYSICAL VAPOR-DEPOSITION METHODS

Tantalum film deposition is performed using a variety of energetic physical vapor deposition methods. The goal is to isolate the common factors in these processes that contribute to phase selection in the deposited Ta films. The techniques examined include bias-magnetron sputtering, ion-assisted evaporation, pulsed laser deposition, and cathodic arc deposition. The microstructure is primarily examined by x-ray diffraction, while resistivity and temperature coefficient of resistivity were determined using a four-point probe. Methods in which the depositing Ta atoms are energetic produce films with the highest fraction of the low resistivity bcc phase. The results further show that there is an optimum range of energetic ion and/or atom bombardment for stabilization of the low resistivity bcc phase. This is expressed in terms of momentum-per-Ta atom deposited during growth.