The electrical resistivity and resistance-temperature characteristics of thin titanium films

In this communication are described the results on the electrical resistivity and resistance-temperature characteristics of titanium films, measured in vacuum. They were evaporated onto soda glass microscope slides at room temperature in a sputter-ion pumped glass belljar vacuum system at about 5×10^-8 torr. The films varied in their thickness from 50 to 1100 Å, and the resistivity was very high for the thinnest films but for the thickest ones it approached approximately double the bulk value. The measured resistivities for the continuous freshly prepared films are too high to be explained on the basis of the Fuchs-Sondheimer theory^{1, 2} for diffuse scattering, and are attributed to porosity and the gaseous impurities taken down during and after their formation. The temperature coefficient of resistance (TCR) was negative for films less than 50–60 Å thick but positive for thicker ones. A bulk mean free path of 285 Å in titanium was calculated at room temperature.