THE CHEMICAL BONDING STATE OF NITROGEN IN KAPTON-DERIVED CARBON-FILM AND ITS EFFECT ON THE GRAPHITIZATION PROCESS

The chemical bonding state of the nitrogen which remains in the carbon films derived from a polyimide Kapton film was studied by X-ray photo electron spectroscope and related to the changes in structure and tran sport properties. The nitrogen remaining after heal treatment up to 22 00 degrees C was in a tertiary bonding state, replacing carbon atoms i n hexagonal layers, which was supported by theoretical calculation bas ed on ab-initio molecular orbital theory. The departure of substituted nitrogen atoms from hexagonal layers showed a good correspondence wit h structure development and changes in transport properties, the prese nce of nitrogen depressing the developments in structure and transport properties. After the departure of nitrogen above 2300 degrees C grap hitization of the films was very remarkable. (C) 1998 Elsevier Science Ltd. All rights reserved.