The oxidation kinetics of thin copper films studied by resistivity measurements

Abstract

Resistivity measurements on thin metal films allow to study the kinetics of oxidation. The method is applied to 50-60 nm thick copper films deposited on glass substrates under UHV conditions. After annealing at 150 °C, the films are exposed to pure oxygen at various temperatures in the range 85-135 °C, and the electrical resistivity is recorded in situ. At these temperatures, the oxygen begins to penetrate into the interior of the films, which results in a relatively steep increase in the film resistivity. A linear time law is valid to good approximation, which can be attributed to the influence of the dissociation of an adsorbed molecular species of oxygen on the reaction velocity. A potential diffusion of oxygen in the grain boundaries is also discussed.