Results presented in this letter demonstrate that the effective channel mobility of lateral, inversion-mode 4H-SiC MOSFETs is increased significantly after passivation SiC/SiO/sub 2/ interface states near conduction band edge by high temperature anneals nitric oxide. Hi-lo capacitance-voltage (C-V) and ac conductance measurements indicate that, at 0.1 eV below edge, trap density decreases from approximately 2/spl times/10/sup 13/ to 12/ eV/sup -1/ cm/sup -2/ following oxide 1175/spl deg/C...

Results of capacitance–voltage measurements are reported for metal–oxide–semiconductor capacitors fabricated using the 4H polytype silicon carbide doped with either nitrogen (n) or aluminum (p). Annealing in nitric oxide after a standard oxidation/reoxidation process results slight increase defect state density lower portion band gap p-SiC and significant decrease states upper half n-SiC. Theoretical calculations provide an explanation these terms N passivating C clusters at...

Over the last two decades, lattice Boltzmann methods have become an increasingly popular tool to compute flow in complex geometries such as porous media. In addition single phase simulations allowing, for example, a precise quantification of permeability sample, number extensions method are available which allow study multiphase and multicomponent flows on pore scale level. this article, we give extensive overview these diffuse interface models discuss their advantages disadvantages....

A modified Deal Grove model for the oxidation of 4H-SiC is presented, which includes removal carbon species. The applied to data on rates (0001) Si, (0001̄) C, and (112̄0) a faces, are performed in 1 atm dry oxygen temperature range 950–1150 °C. Analysis within provides physical explanation large crystal-face dependent observed.

Specific contact resistances measured at elevated temperatures for Ni ohmic contacts to 6H-SiC were reported. The specific with the linear transmission line method both room temperature and 500 °C yielded values <5×10−6 Ω cm2 temperatures. trend shows a decreasing resistance higher annealed metal film is nickel silicide substantial mixing of C throughout layer.

The specific contact resistance of an ohmic will be discussed including ways to calculate and measure this parameter. Ohmic contacts n- p-type hexagonal SiC then detailed. Low n-type are predominately fabricated by annealing a refractory metal, thereby forming silicide with lowered Schottky barrier height at the metal–SiC interface. P-type on other hand generally use Al or alloys which upon enable diffuse into thus resulting in properties. Aluminium however suffer from many problems...

Unlike the Si-SiO2 interface, SiC-SiO2 interface has large defect densities. Though nitridation been shown to reduce density, effect of H remains an open issue. Here we combine experimental data and results first-principles calculations demonstrate that a Si-C-O bonded interlayer with correlated threefold-coordinated C atoms accounts for observed states, passivation by N atomic H, nature residual defects.

Nitridation of the SiO2/SiC interface yields a reduction in state density, immunity to electron injection, as well increased hole trapping. It is shown that accumulation nitrogen at oxide/semiconductor solely responsible for these three effects. The evolution density states, traps, and traps measured metal-oxide-semiconductor capacitors function content which varied by adjusting gate oxide NO annealing time. A rate equation derived model change observed various energy levels, terms binding...

In this paper we quantify the influence of geometry and distribution surface roughness to directional anisotropy fluid flow transport properties a single fracture. Roughness fractures appears have first order control on how they behave mechanically hydraulically. We directly quantified fracture using high‐resolution laser scanning confocal microscopy. This was input into coupled numerical models transport. simulated colloids (microspheres) through found tailing in breakthrough sensitivity...

The direct impact of the SiO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> /4H-SiC interface state density ( <i xmlns:xlink="http://www.w3.org/1999/xlink">D</i> xmlns:xlink="http://www.w3.org/1999/xlink">it</sub> ) on channel mobility lateral field-effect transistors is studied by tailoring trap distribution via nitridation thermal gate oxide. We observe that scales like inverse charged density, which consistent with...

Patterns of person-to-person contacts relevant for infectious diseases transmission are still poorly quantified in Sub-Saharan Africa (SSA), where socio-demographic structures and behavioral attitudes expected to be different from those more developed countries.We conducted a diary-based survey on daily time-use individuals ages one rural peri-urban site Manicaland, Zimbabwe. A total 2,490 diaries were collected used derive age-structured contact matrices, analyze time spent by settings,...

The administration of estradiol, testosterone, desoxycorticosterone, progesterone and diethylstilboestrol to normal rats induced in some animals an elevation blood pressure hypertensive levels. It is suggested that this effect due renal injury since it could be abolished by the extracts other evidence points changes occurring kidney following use these substances. occurrence hypertension certain cases Cushing9s disease or adreno-genital syndrome attributed formation abnormal steroid...

Calcareous nannofossil assemblages have been investigated in three sections from around the margins of Early Cretaceous North Sea Basin. Both absolute (number nannofossils per gram) and relative (percent assemblage different taxa) abundance data collected. Absolute abundances (up to 10 billion are somewhat higher than those reported previously other stratigraphic intervals. Stratigraphic correlation trends points toward existence large, uniform water masses, stable over long (0.5 1 m.y.)...

We report the effect of processing variables on inversion layer electron mobility (0001)-oriented 4H-SiC n-channel MOSFETs. The process investigated include: i) implant anneal temperature and ambient; ii) oxidation procedure; iii) postoxidation annealing in nitric oxide (NO); iv) type gate material, v) high-temperature ohmic contact anneal. Electron is significantly increased by a NO, but other variations have only minor effects channel mobility. also dependence for NO non-NO annealed

Specific contact resistance measurements are reported for Al-Ti ohmic contacts to epitaxial p-type 6H-SiC as a function of doping. The circular transmission line method was used measure the specific including sheet layer and modified under contact. Epitaxial layers with Al doping between 5.5×1015 2×1019 cm−3 yielded resistances 2.9×10−2 1.5×10−5 Ω cm2. A good theoretical fit data obtained by assuming metal-6H-SiC barrier height equal 0.37 eV.

FAMILIAL polyposis of the colon may be associated with osteomas, fibromas and sebaceous cysts in Gardner syndrome,1 endocrine adenomatosis2 brain tumors.3 The association tumors was reported by Turcot et al.3 1959. To our knowledge family herein (Fig. 1) is second example this syndrome.Case ReportCase 1. D.F. (B.M.H. 49262), a 12-year-old girl, hospitalized on August 8, 1965, 2 weeks after seizure involving right arm leg. She also complained frontal headache diarrhea. Her father, who 47, her...

Isolated hills and uplands in the River Lowland.These rocks are apparently sourc~~ of saline water unconsolidated deposits

T. Hagyard and J. R. Williams, Trans. Faraday Soc., 1961, 57, 2288 DOI: 10.1039/TF9615702288

Phosphorous from P <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> O xmlns:xlink="http://www.w3.org/1999/xlink">5</sub> is more effective than nitrogen for passivating the 4H-SiC/SiO interface. The peak value of field-effect mobility 4H-SiC metal-oxide-semiconductor transistors (MOSFETs) after phosphorus passivation approximately 80 cm <sup xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> /V·s. However, converts SiO layer to...