DOUBLE SOI STRUCTURES AND DEVICE APPLICATIONS WITH HETEROEPITAXIAL AL2O3 AND SI

Growth and properties of a double SOI (Si-on-insulator) structure, whi ch consists of epitaxial Al2O3 as an insulator layer and epitaxial Si layers, are discussed. LP-CVD (low-pressure chemical vapor deposition) for gamma-Al2O3 (100) growth on Si(100) substrates was combined with Si CVD through a sample exchanging chamber with reflection high-energy electron diffraction (RHEED) and quadrupole mass spectrometer (QMS) t o grow successively and analyzed without exposure to air. These epitax ial multilayers were characterized by RHEED, Auger electron spectrosco py (AES), cross-sectional transmissin electron microscopy (TEM) and et ching method. Metal-oxide-semiconductor (MOS) field effect transistor (FET) mobility was also studied on each Si layer. Both Si layers showe d similar defect density and mobility. This double SOI structure was a pplied to fabrication of a pressure sensor for use at elevated tempera tures up to 300 degrees C.