The structural properties of silicon oxynitride films grown in a N 2 O environment at temperatures higher than 900°C and for use as gate dielectrics in vertically diffused power metal oxide semiconductor field effect transistor ͑PowerVDMOS͒ technologies have been studied by means of X-ray photoelectron spectroscopy. The progressive modifications of the bonding environments upon reaching the oxynitride-silicon interface have been analyzed as well as of the relation between these modifications and the selected oxynitridation process. The results show that the chemistry of the oxynitride layer is a rather complex one, and it significantly and progressively changes by moving toward the silicon interface, in a way strongly affected by the growth process. In particular, the medium thermal budget processes ͑950°C, 20-60 min͒ favor the formation of a relatively uniform distribution of the single oxidized O-N-Si 2 bonds both at the interface and throughout its immediate backstage. Such findings can help in assessing the role played by the nitridation process in the quality and reliability performances of the final device.In the last few years, silicon oxynitride thin films have been proposed as an alternative to SiO 2 as a thin gate dielectric for microelectronics applications. As the scale of integration increases and the thickness of the dielectric is reduced, the SiO 2 dielectric layer properties get less and less sufficient to reliably withstand the increasing electric field. As a consequence, the device degradation due to the high leakage currents and even gate rupture shows up at a higher rate. Silicon oxynitrides ͑SiO x N y ͒ are materials with a higher dielectric constant and, in thin layer form, exhibit reduced susceptibility to interface state generation with respect to SiO 2 , higher timeto-breakdown values and reliability, improved I-V and C-V characteristics. 1-3 Therefore, silicon oxynitride could eventually replace thin gate dielectrics characterized by a smaller thickness but an equal capacitance, thus assuring an improved robustness of the device. In this context, several analyses have been performed to characterize SiO x N y film quality in terms of both device performance and processing. 4,5 A clear understanding of the structure and chemical composition of the oxynitride film could be valuable help in assessing its quality as a gate layer in power devices. Nevertheless, in many works found in the literature, the only relevant parameter taken into account is the overall nitrogen content. In the attempt to disclose the role of the oxynitride structure in the electrical defectivity and reliability, it is of fundamental importance to know the nitrogen bonding configurations present at the silicon substrate interface and their relation with the selected oxynitridation process. In this respect, X-ray photoemission spectroscopy ͑XPS͒ is a powerful tool to perform a compositional analysis and also to investigate the relative bonding arrangements of silicon, oxygen, and nitrogen atoms. The aim of the present wo...

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Ultraviolet (UV) monitoring is of great interest in the healthcare field to prevent excessive UV exposure risks. In the last years silicon carbide (SiC) has emerged as a suitable material for the fabrication of UV detectors. In this paper we propose a 4H-SiC Schottky photodiode with a continuous very thin Ni2Si layer operating at 0V, properly designed for UV radiation monitoring.

Heating (100) silicon at high temperature (say, higher than 850• C) in H 2 , cooling to 670-700 • C in the same ambient, and quenching to room temperature in N 2 results in environmentally robust, terraced 1 × 1 (100) SiH 2 . Evidence for this conclusion is based on angle-resolved x-ray photoelectron spectroscopy, atomic force microscopy, infrared absorption spectroscopy in the attenuated total reflection mode, thermal programmed desorption, and reflection high-energy electron diffraction.

Triple crystal diffractometry, x-ray standing wave, and transmission electron microscopy investigation of shallow BF 2 implantation in Si Si wafers implanted at 80 keV with different As doses, and next annealed at different temperatures for different times, were studied by means of x-ray triple crystal diffraction, x-ray standing wave, transmission electron microscopy, spreading resistance profile, and electrochemical C-V profiling methods. The implantation processes produced heavily damaged subsurface regions hundreds of nanometers deep. By fitting both the x-ray diffraction curves and the x-ray standing wave photoelectron emission profiles, it was possible to determine the most appropriate strain and atomic static displacement behavior versus depth within the disturbed region of the crystal. The results obtained by x-ray diffraction measurements were confirmed by transmission electron microscopy investigations. Therefore, making use of different structural and electrical characterization techniques it was possible to find: ͑i͒ the depth of amorphization of the implanted regions, ͑ii͒ the appearance of extended defects ͑dislocation loops band͒ during the restoration of the lattice by the annealing processes and the dependence of their size and density on the implant dose and the annealing time and temperature, ͑iii͒ the dopant profiles versus depth as a function of the implant dose and the annealing parameters, ͑iv͒ the effect on the total strain of the doping induced variation of the conduction band minima. The experimental evidence of a screen electronic effect on the As + -Si distance in the restored crystal lattice was confirmed by ab initio calculations.