X-ray Reflectivity Studies of Aromatic Polyimide Langmuir-Blodgett Films

Polyimides are well known as highly thermally stable engineering plastics and are widely used as insulating materials in electronic applications. We prepared highly ordered multilayers of aromatic polyimides by Langmuir-Blodgett technique with the precursor method of different thickness up to 500 ÅX-ray reflectivity data exhibit the strongly periodic modulated electron density normal to the substrate surface due to aromatic and alkyl chain parts of the repeatunit. We measured a thickness of 18 Åper monolayer. Additionally, the highly correlated structure is supported by bragg-like peaks measured by X-ray diffuse scattering. Their structural behavior before and after thermal treatment investigated by specular and non-specular X-ray reflectivity will be discussed.