Structure and Electrical Properties of Evaporated and Sputtered Titanium Films

The structure, specific resistivity and temperature coefficient of resistivity of titanium films between 200 and 2000 Å thick will be discussed. The films were deposited on soft glass substrates by sputtering in an argon atmosphere and by evaporation. The effects of additions of nitrogen or oxygen to the argon on the structure and electrical properties of sputtered titanium films were evaluated. There is evidence that the range of specific resistivities and temperature coefficients found for titanium films deposited by different techniques is caused by interstitial impurities which are present in various amounts during the deposition processes. Evaporated titanium films generally had a lower specific resistivity and a higher temperature coefficient than sputtered titanium films of comparable thickness due to a lower impurity content. Larger additions of nitrogen and oxygen to the argon while sputtering led to the formation of a number of titanium compounds.