ISSN:
1573-4889
Keywords:
desorption of oxygen
;
transmission electron microscopy
;
in situ oxidation studies
;
oxidation of thin films
;
nucleation of oxides
Source:
Springer Online Journal Archives 1860-2000
Topics:
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
Notes:
Abstract Partly oxidized copper films were annealed in a controlled vacuum of 10−7 Pa at a temperature of 450° C. The changes discussed below were observed in situ with a specially designed high-resolution transmission electron microscope. The thin, (100)-oriented, single-crystal films of copper had been oxidized immediately prior to the annealing studies at the same temperature and at an oxygen partial pressure of 7×10 −1 Pa, until the desired fraction of the copper film was converted to oxide. It was observed that the oxide disappeared during annealing as long as some copper was left unoxidized. The disappearance of the oxide is explained as being due to dissociation of the oxide at the oxide-metal interface followed by diffusion of oxygen into the metal and desorption of oxygen from the surface of the unoxidized copper. The rate of disappearance of the oxide was found to be proportional to the surface area of unoxidized copper, i.e., the desorption was found to be the rate — limiting step. In the case of heavily oxidized films (〉50%), holes were observed to develop in the oxide near the oxide-metal interface after an annealing period of 2–3 hr. Upon resumption of the oxidation, these holes first disappeared, and the normal oxidation behavior was then resumed. The formation of holes may be explained by vacancy clustering. When completely oxidized films were annealed, recrystallization of the oxide was observed.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00618245
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