Several conductive structures which appeared to be usable as base electrodes in VLSI capacitors based on high dielectric materials have been annealed in oxygen at 650 °C. The studied structures were Pt/TiN, Pt/Ta, Au/TiN, Ru, and RuO2/Ru, prepared under a variety of conditions. The structures have been studied by Rutherford backscattering (RBS) and Auger Electron Spectroscopy (AES). It was found that none of the pure metals, Pt, Au, or Ru, can prevent the diffusion of oxygen to the underlying layer and its oxidation, thus causing a possible break in the electrical conduction path to the silicon substrate. Of the investigated materials, in the thickness range ≤ 110 nm only the RuO2/Ru couple preserved its electrical connectivity to the Si substrate and prevented diffusion of silicon to the surface of the electrode.

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High purity copper has been deposited from trialkyl phosphine complexes of cyclopentadienyl and methylcyclopentadienyl copper(I) by thermal chemical vapor deposition (CVD). Films as thick as 4.4 μm have been deposited at growth rates of up to 2000 Å/min with resistivites typically 2.0 μΩ cm, just slightly higher than bulk copper. Depositions were carried out at substrate temperatures between 150 and 220 °C on a variety of substrates including Si, SiO2, polyimide, and Cr/Cu. At low substrate temperatures, copper film growth appears to show some selectivity for transition metal surfaces. An activation energy of 18 kcal/mole has been measured for film growth on Cu seeded substrates. CVD copper films have been characterized by Auger spectroscopy which showed that carbon and oxygen levels are below the limits of detection. Transmission electron microscopy revealed that the copper grain size was ∼0.6μm and the grain boundaries are free of precipitates. Films show good conformality.

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Several conductive structures, which appeared to be usable as base electrodes for integrated devices based on high dielectric materials, have been annealed for 30 minutes in oxygen at 650 °C. Similar structures coated with lead-based ferroelectrics deposited by the sol-gel method have been annealed for 1 min in oxygen at higher temperatures. The materials have been characterized by Rutherford backscattering (RBS) and scanning electron microscopy (SEM) and the crystallographic structure of the ferroelectrics films has been determined by X-ray diffractometry (XRD).Only RuO2/Ru has been found to be suitable as an electrode, at temperatures not exceeding 650 °C. It has also been found that the electrode materials can strongly affect the crystallization behavior of the sol-gel ferroelectric films and the formation of single-phase perovskite layers.