G. Ottaviani

Bio: G. Ottaviani is an academic researcher. The author has contributed to research in topics: Drift velocity & Silicon. The author has an hindex of 5, co-authored 6 publications receiving 590 citations.

Electron and hole drift velocity measurements in silicon and their empirical relation to electric field and temperature

Abstract: The drift velocity of electrons and holes in silicon has been measured in a large range of the electric fields (from 3 . 102to 6 . 104V/cm) at temperatures up to 430 K. The experimental data have been fitted with a simple formula for the temperatures of interest. The mean square deviation was in all cases less than 3.8 percent. A more general formula has also been derived which allows to obtain by extrapolation drift velocity data at any temperature and electric field.

Measurement of the drift velocity of charge carriers in mercuric iodide

Abstract: The time‐of‐flight technique has been used to determine the electron and hole drift velocities in mercuric iodide crystals. The electron mobility is constant up to fields of 30 kV/cm, equal to 100 cm2/V sec at room temperature, and proportional to T−0.9 in the temperature range 114–300 °K. The hole mobility is equal to 4 cm2/V sec at room temperature and exhibits a T−1.7 dependence between 140 and 240 °K and a T−3.7 dependence between 240 and 350 °K.

Some aspects of Ge epitaxial growth by solid solution

Abstract: Epitaxial growth of a germanium layer of 0.4–1.1 μm was obtained at 350 °C by the dissolution and transport of an amorphous semiconductor layer through an aluminum film using the Ge (bulk)/Al (evaporated)/Ge (evaporated) structure. Transport and growth were studied by scanning electron microscopy (SEM) and 4He+ backscattering. Channeling measurements indicate that the grown layer is well aligned with the underlying 〈111〉 substrate. Electrical measurements indicate that the grown layer is heavily doped p type. The sputtering cleaning procedure before evaporation is necessary to provide a proper Ge (bulk)/Al interface for nucleation and growth. This effect was verified by measurements of the dissolution rate of Ge in Al film.

Current saturation in zero-bandgap, top-gated graphene field-effect transistors.

Abstract: The first observation of saturating transistor characteristics in a graphene field-effect transistor is reported. The saturation velocity is attributed to scattering by interfacial phonons in the silicon dioxide layer supporting the graphene channels. These results demonstrate the feasibility of graphene devices for analogue and radio-frequency circuit applications without the need for bandgap engineering.

Electron and hole drift velocity measurements in silicon and their empirical relation to electric field and temperature

Abstract: The drift velocity of electrons and holes in silicon has been measured in a large range of the electric fields (from 3 . 102to 6 . 104V/cm) at temperatures up to 430 K. The experimental data have been fitted with a simple formula for the temperatures of interest. The mean square deviation was in all cases less than 3.8 percent. A more general formula has also been derived which allows to obtain by extrapolation drift velocity data at any temperature and electric field.

Carrier mobilities in silicon semi-empirically related to temperature, doping and injection level

Abstract: From a review of different publications on the carrier mobilities in silicon, the authors propose an approximated calculation procedure which permits a quick and accurate evaluation of these mobilities over a large range of temperatures, doping concentrations and injection-levels. The proposed relations are well adapted to semiconductor device simulation becuase they allow short computation times.

MINIMOS—A two-dimensional MOS transistor analyzer

Abstract: We describe a user-oriented software tool-MINIMOS-for the two-dimensional numerical simulation of planar MOS transistors. The fundamental semiconductor equations are solved with sophisticated programming techniques to allow very low computer costs. The program is able to calculate the doping profiles from the technological parameters specified by the user. A new mobility model has been implemented which takes into account the dependence on the impurity concentration, electric field, temperature, and especially the distance to the Si-SiO 2 interface. The power of the program is shown by calculating the two-dimensional internal behavior of three MOST's with 1-µm gate length differing in respect to the ion-implantation steps. In this way, the threshold voltage shift by a shallow implantation and the suppression of punchthrough by a deep implantation are demonstrated. By calculating the output characteristics without and with mobility reduction, the essential influence of this effect is shown. From the subthreshold characteristics, the suppression of short-channel effects by ion implantation becomes apparent. The MINIMOS program is available for everyone for just the handling costs.

Relation of drift velocity to low‐field mobility and high‐field saturation velocity

Abstract: From an investigation of the behavior of the momentum distribution function of electrons or holes under scattering rate and momentum scaling transformations, a number of interesting results are derived concerning the parameterization of drift‐velocity–vs–electric‐field relations in terms of mobility and saturation velocity. Indeed it is determined that saturation velocity is invariant under scaling of the magnitude of the scattering rates, which alters mobility, while mobility is invariant under scaling of the magnitude of the momentum, which alters saturation velocity. This independence between mobility and saturation velocity is utilized to generalize to interfaces velocity‐field relations valid the the bulk. Using the transformation of drift velocity under both rate and momentum scaling, partial experimental data can be used to predict high‐field saturation velocities. These velocities need not be reduced due to higher scattering rates as much as their low‐field counterparts. Nonzero magnetic fields and nonuniform scaling are also considered.