Journal of the Electrochemical Society, Vol.144, No.5, 1849-1854, 1997
A Low-Temperature Collimated Titanium Deposition Process
Bg depositing collimated titanium at near room temperature, a preferred (002) oriented Ti film is formed. These (002) Ti films showed uniform grain size distributions and a smooth surface topography. In contrast, collimated Ti using conventional deposition temperatures (approximate to 175 degrees C) results in a (101) Ti and (002) Ti mixed orientation, bimodal grain size distributions, and a rough surface topography. The measured resistivity of the low temperature film is 63 mu Omega cm which is close to that of 60 mu Omega cm, attained by collimated processing at elevated temperatures. The film stress for the low temperature 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 bottom of deep contacts with an aspect ratio of 3:1 showed excellent bottom surface coverage. In addition, lower via resistance values have been obtained using the low temperature collimated Ti process.
Keywords:GROWTH