Effect of the sputtering ambient contamination on the microstructure of Al–Si films

Abstract
In this work we report the results of a study on the effects of the deposition parameters on the microstructure of sputtered Al–1% Si thin films, performed using x-ray diffraction techniques. In particular, preferred growth and texture were evaluated for films deposited with controlled amounts of contaminating gases in the sputtering ambient. Films deposited without any addition of contaminants show both a preferred growth along {111} planes and a strong texture, which appears to be a function of the deposition temperature. On the contrary, films deposited in an atmosphere containing contaminants like N2, CO2, O2 and H2O, appear to be more ‘‘powderlike,’’ with less—if any—preferred growth and texture. Electromigration tests show a better electromigration resistance for films grown in cleaner ambient. An interpretation of the results is given, which involves the different nucleation and growth processes for clean and contaminated films.