AL REFLOW STUDIES FOR DEEP-SUBMICRON STRUCTURES - PROPERTIES AND MICROSTRUCTURE

The aluminium filling process of vias is studied as a function of time . New insights in the aluminium transport mechanism have been obtained . As a result of both (Al, Ti)-compound formation and overhang during the aluminium deposition the partly filled via is closed. The driving force for void elimination is the minimization of the surface free ene rgy. Material transport via dislocation mobility is suggested to play a major role during filling of the cavity. Electrical measurements of via strings showed a strong dependence on the liner (thickness and com position). A high yield of low via resistances has been obtained.