A complete analysis of HfO 2 high k thin layers deposited by metal organic chemical vapour deposition (MOCVD) is made by infrared spectroscopy using different optical configurations. Multiple internal reflection (MIR) and attenuated total reflection (ATR) are used, giving information about morphology and composition of the layers. Samples under investigation are HfO 2 layer of 3 to 12 nm thick deposited at 400 and 550°C on thin silicon oxide. MIR technique elucidates carbon content in the layer and ATR informs about the interface evolution, and the crystalline character of the HfO 2 layer. The high sensitivity of MIR coupled with the large spectral range available of ATR allow the full characterisation of these layers.

The quality of the interface between a HfO2 high-k gate dielectric and the Si substrate directly influences its electrical properties. The chemical composition of the interfacial region of HfO2 deposited on a SiO2∕Si(100) substrate by pulsed liquid injection metal organic chemical vapor deposition at 430 and 550°C was investigated by medium energy ion scattering, angular resolved x-ray photoemission spectroscopy analysis, and high resolution transmission electron microscopy. It is shown that the HfO2∕SiO2 interface is abrupt with low roughness and no silicate. The interface roughness with SiO2 is found to be close to that generally measured in silicon technology (silicon oxide above silicon substrates) [E. A. Irene, Solid-State Electron., 45, 1207 (2001)]. The analysis of the experimental results indicates that the deposition technique does not lead to the formation of an extended silicate layer at the HfO2∕SiO2 interface.

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The integration of III-V/Si hybrid lasers on a 300 mm platform for photonic applications requires the development of dedicated CMOS-compatible contacts, for which nickel-based ones are very good candidates. In this scope, this work presents and compares the impact of in situ preclean based on argon (Ar) or helium (He) plasma on the surface integrity of InP prior to the nickel (Ni) contact deposition. The resulting surface morphology, element distribution, phase formation sequence of the Ni/InP system, and electrical behavior of Ni/n-InP contacts are detailed using morphological, structural, and electrical characterizations. The results show that Ar preclean significantly damages the InP surface by generating high roughness and creating indium (In) dots on the top surface, while He preclean seems to induce lighter damages and no In dots. Although the phase sequence of the Ni/InP system is overall the same for each preclean, the electrical behavior differs depending on the nature of the preclean. On one hand, Ni/n-InP Ar-precleaned contacts exhibit nonohmic behavior for each investigated thermal budget. On the other hand, He-precleaned contacts features ohmic behavior for the as-deposited state and thermal anneals up to 350°C for 60 s. They, however, become nonohmic after anneals of 400 and 450°C for 60 s. These results, hence, suggest that the difference of electrical behavior obtained between Ar and He-precleaned Ni/n-InP contacts is due to differences in the state surface and morphology.

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