Oxides form a class of material which covers almost all the spectra of functionalities : dielectricity, semiconductivity, metallicity superconductivity, non-linear optics, acoustics, piezoelectricity, ferroelectricity, ferromagnetism...In this thesis, crystalline oxides have beenintegrated on the workhorse of the semiconductor industry, the silicon, by Molecular Beam Epitaxy (MBE).The first great interest of the epitaxial growth of crystalline oxides on silicon consists in the application of "high-k" dielectric for future sub-22nm CMOS technology. Gadoliniumoxide was explored in detail as a promising candidate of the alternative of SiO2. The pseudomorphic epitaxial growth of Gd2O3 on Si (111) was realized by identifying the optimal growth conditions. The Gd2O3 films show good dielectric properties and particularly an EOTof 0.73nm with a leakage current consistent with the requirements of ITRS for the sub-22nmnodes. In addition, the dielectric behavior of Gd2O3 thin films was further improved by performing PDA treatments. The second research interest on crystalline oxide/Si platform results from its potential application for the "More than Moore" and "Heterogeneous integration" technologies. TheSrTiO3/Si (001) was intensively studied as a paradigm of the integration of oxides on semiconductors. The crystallinity, interface and surface qualities and relaxation process of the STO films on silicon grown at the optimal conditions were investigated and analyzed. Several optimized growth processes were carried out and compared. Finally a "substrate-like" STO thin film was obtained on the silicon substrate with good crystallinity and atomic flat surface. Based on the Gd2O3/Si and SrTiO3/Si templates, diverse functionalities were integrated on the silicon substrate, such as ferro-(piezo-)electricity (BaTiO3, PZT and PMN-PT),ferromagnetism (LSMO) and optoelectronics (Ge). These functional materials epitaxially grown on Si can be widely used for storage memories, lasers and solar cells, etc.
| Identifer | oai:union.ndltd.org:CCSD/oai:tel.archives-ouvertes.fr:tel-00601689 |
| Date | 20 October 2010 |
| Creators | Niu, Gang |
| Publisher | Ecole Centrale de Lyon |
| Source Sets | CCSD theses-EN-ligne, France |
| Language | English |
| Detected Language | English |
| Type | PhD thesis |
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