Articles you may be interested inVisible to vacuum ultraviolet dielectric functions of epitaxial graphene on 3C and 4H SiC polytypes determined by spectroscopic ellipsometry Details of below band-gap uniaxial dielectric function of SiC polytypes studied by spectroscopic ellipsometry and polarized light transmission spectroscopy Spectroscopic rotating-analyzer ellipsometry employing a compensator and optical transmission were used to measure the dielectric functions of bulk 4H and 6H SiC from 0.72 to 6.6 eV for light propagating nearly parallel to the hexagonal axis. The measurements below the band gap show the presence of a thin surface layer, which was modeled as SiO 2 . The data are similar to results for cubic ͑3C͒ and 6H SiC from the literature, but differences are notable, particularly above 4 eV. At 5.56 eV, we observe a critical point in 4H SiC, which is assigned to direct interband transitions along the UϭM ϪL axis in the hexagonal Brillouin zone after comparison with band structure calculations. No evidence for direct transitions below 6.5 eV was found in 6H SiC. We apply our results to the analysis of a 4H SiC film on insulator ͑SiCOI͒ produced by high-dose hydrogen implantation and direct wafer bonding on Si. For comparison, we also studied a 1 m thick epitaxial layer of 3C SiC on Si, where the interference oscillations are influenced by surface and interface roughness.

HfO 2 films deposited via tetrakis diethylamido hafnium ͑TDEAH͒ precursor using MOCVD ͑metal organic chemical vapor deposition͒ are presented. TDEAH is a promising precursor candidate for the deposition of high permittivity gate dielectrics. We report the impact of process and annealing conditions on the physical and electrical properties of the film. Deposition and annealing temperatures influence the microstructure, density, and impurity levels of TDEAH HfO 2 films. Spectroscopic ellipsometry shows that film microstructure manifests itself in the optical properties of the film, particularly in the presence of a band edge related feature at 5.8 eV. An impurity analysis using Auger electron spectroscopy, secondary ion mass spectroscopy, and Raman spectroscopy, indicates that carbon impurities from the precursor exist as clusters within the HfO 2 dielectric. The impact of deposition temperature and annealing temperature on the capacitance vs. voltage and current density vs. voltage characteristics of platinum gated capacitors is studied. Correlation of physical film properties with the capacitance and leakage behavior of the TDEAH HfO 2 films indicates that impurities, in the form of carbon clusters, and low HfO 2 film density are detrimental to the electrical performance of the gate dielectric.As the smallest feature size on a microprocessor approaches 50 nm, the primary dielectric layer in the field effect transistor, referred to as the gate dielectric or gate oxide, will thin to below 15 Å. Around this thickness, electrical leakage current through the dielectric becomes excessive and is expected to cause problems due to either high power dissipation or circuit reliability. 1 One solution to this problem is to replace SiO 2 dielectrics with higher permittivity dielectrics. A higher permittivity dielectric can be thicker and still achieve the same capacitance as a thinner SiO 2 dielectric. The starting point for identifying possible replacements for SiO 2 dielectrics is to evaluate their thermal stability in direct contact with silicon. Reactions between the high permittivity dielectric and the silicon substrate or electrode are undesirable. Extensive thermodynamic calculations have been performed by Hubbard and Schlom, 2 identifying numerous binary and ternary oxides that are candidate materials. Some of the binary oxides that are leading contenders for replacing SiO 2 include: ZrO 2 , HfO 2 , Y 2 O 3 , and Al 2 O 3 . In addition, there are numerous ternary ͑or mixed͒ oxides that have also been predicted, or experimentally determined, to be stable in contact with silicon.In general, the class IIIB and IVB oxides tend to be the most thermodynamically stable oxides for potential use in integrated circuit manufacturing. Doping the IIIB and IVB oxides with Al 2 O 3 or SiO 2 increases the crystallization temperature. Such amorphous dielectrics are desirable because grain boundaries enhance diffusion of dopants from the electrode to the substrate and possibly contribute to electrical leakage. On the other hand, doping...

This ietter reports the results obtained with planar p-i-n photodiodes realized using three different passivating coatings and compares their performances and long-term stability in view of highly reliable component development.

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Articles you may be interested inSecondary ion mass spectrometry characterization of source/drain junctions for strained silicon channel metal-oxide-semiconductor field-effect transistors Two-dimensional characterization of carrier concentration in metal-oxide-semiconductor field-effect transistors with the use of scanning tunneling microscopy Scanning capacitance microscopy imaging of silicon metal-oxide-semiconductor field effect transistors Two dimensional dopant and carrier profiles obtained by scanning capacitance microscopy on an actively biased cross-sectioned metal-oxide-semiconductor field-effect transistor Comparison of two-dimensional carrier profiles in metal-oxide-semiconductor field-effect transistor structures obtained with scanning spreading resistance microscopy and inverse modeling