Optical Transmittance of Partially Oxidized Copper Films

Publisher Website
Google Scholar
Abstract
The optical transmittance, measured from 400 to 800 μm during the complete oxidation of copper films to CuO0.67 at temperatures below 200 °C, has been used to test a model of oxidation by parallel layers. The transmittance at each stage of oxidation was calculated from the thickness of the oxide and metal layers, the optical constants, and the assumption that two homogeneous parallel absorbing layers exist at all stages. By comparing the calculated and experimental values of transmittance, the validity of the “parallel layer” model was established for nearly all stages of oxidation. Deviations in the initial stages are attributed to nucleation. Films oxidized at temperatures exceeding 147°C showed evidence of agglomeration of the metal in the terminal stages of oxidation. The films, deposited at 25°C on Pyrex substrates, are strained. Thus, when they were heated to the oxidizing temperatures of 125°–200°C, they were oxidized and also annealed. The optical constants for strained copper films are compared with those for annealed films at 400, 450, 500, 550, and 700 μm. Calculated changes in the transmittance at 550 μm are given for the parallel-layer oxidation of annealed copper films initially 200 to 700 Å thick.

This publication has 0 references indexed in Scilit: