A LOW-TEMPERATURE COLLIMATED TITANIUM DEPOSITION PROCESS

Bg depositing collimated titanium at near room temperature, a preferre d (002) oriented Ti film is formed. These (002) Ti films showed unifor m grain size distributions and a smooth surface topography. In contras t, collimated Ti using conventional deposition temperatures (approxima te to 175 degrees C) results in a (101) Ti and (002) Ti mixed orientat ion, bimodal grain size distributions, and a rough surface topography. The measured resistivity of the low temperature film is 63 mu Omega c m which is close to that of 60 mu Omega cm, attained by collimated pro cessing at elevated temperatures. The film stress for the low temperat ure collimated Ti layer is 1.0 E9 dynes/cm(2) compressive, while it is 1.3 E9 dynes/cm(2) tensile for the conventional col limated Ti layers . Low temperature collimated Ti deposited as a contact layer at the bo ttom of deep contacts with an aspect ratio of 3:1 showed excellent bot tom surface coverage. In addition, lower via resistance values have be en obtained using the low temperature collimated Ti process.