日本金属学会誌

J. Japan Inst. Metals, Vol. 54, No. 4 (1990),
pp. 480-484

Effect of Impurities and Deposition Condition on Electrical Resistivity of Titanium Thin Film

Hitoshi Nakamura1 and Masahiro Kitada1

1Central Research Laboratory, Hitachi, Ltd., Kokubunji, Tokyo

Abstract:

The effect of impurities and deposition condition on the electrical resistivity of titanium thin film is investigated. The titanium thin films are deposited by a conventional electron beam system in a vacuum of 10-8 ~ 10-4 Pa. The purities of the titanium deposition sources used are 3N (99.9 mass%Ti), 4N (99.99 mass%Ti; O2~300 ppm) and 4N up (99.99 mass%Ti; O2<200 ppm). The substrate temperature is 473 K and the deposition rate is 0.5~0.7 nm/s. The thickness of titanium thin films is 150 nm. The electrical resistivity of titanium thin films is measured by the four-probe method. The impurity contents in titanium thin films are measured by SIMS. The results are as follows. The electrical resistivity of titanium thin films decreases with increasing vacuum pressure and decreasing impurity content. The average grain diameter of titanium thin films deposited in a vacuum of 10-8 ~ 10-4 Pa using the same source increases with increasing vacuum pressure. The contribution of grain boundary scattering to the electrical resistivity is analyzed using the Mayadas and Shatzkes's equation. As a result, it is found that the vacuum pressure causes a change in grain diameters, thus affecting the electrical resistivity of titanium thin films. Moreover, a good relationship is obtained between the electrical resistivity subtracted the contribution of grain boundary scattering and the oxygen content in titanium thin films. On the other hand, the average grain diameter of titanium thin films deposited in the same vacuum using different sources increases with decreasing impurity content. It is thought that the electrical resistivity of titanium thin films deposited using different sources is influenced by the oxygen content and other impurity metal contents in the deposition sources, except for the contribution of grain boundary scattering.


(Received 1989/10/16)

Keywords:

titanium, electrical resistivity, thin film, vacuum pressure, grain diameter, oxygen, impurity


PDF(Free)PDF (Free)     Table of ContentsTable of Contents

Please do not copy without permission.