This paper reviews the present knowledge of charge transport properties in silicon, with special emphasis on their application in the design of solid-state devices. Therefore, most attention is devoted to experimental findings in the temperature range around 300 K and to high-field properties. Phenomenological expressions are given, when possible, for the most important transport quantities as functions of temperature, field or impurity concentration. The discussion is limited to bulk properties, with only a few comments on surface transport.

A review of some charge transport properties of silicon

The EUV Imaging Spectrometer (EIS) on Hinode will observe solar corona and upper transition region emission lines in the wavelength ranges 170 – 210 A and 250 – 290 A. The line centroid positions and profile widths will allow plasma velocities and turbulent or non-thermal line broadenings to be measured. We will derive local plasma temperatures and densities from the line intensities. The spectra will allow accurate determination of differential emission measure and element abundances within a variety of corona and transition region structures. These powerful spectroscopic diagnostics will allow identification and characterization of magnetic reconnection and wave propagation processes in the upper solar atmosphere. We will also directly study the detailed evolution and heating of coronal loops. The EIS instrument incorporates a unique two element, normal incidence design. The optics are coated with optimized multilayer coatings. We have selected highly efficient, backside-illuminated, thinned CCDs. These design features result in an instrument that has significantly greater effective area than previous orbiting EUV spectrographs with typical active region 2 – 5 s exposure times in the brightest lines. EIS can scan a field of 6×8.5 arc min with spatial and velocity scales of 1 arc sec and 25 km s−1 per pixel. The instrument design, its absolute calibration, and performance are described in detail in this paper. EIS will be used along with the Solar Optical Telescope (SOT) and the X-ray Telescope (XRT) for a wide range of studies of the solar atmosphere.

http://www.rxollc.com/windt/papers/2007_SolPhys_243_19.pdf

The EUV Imaging Spectrometer for Hinode

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.

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

Drift velocity of electrons and holes and associated anisotropic effects in silicon

The phenomenology is reviewed for several enhanced diffusion mechanisms: the normal ionization-enhanced diffusion mechanism, the Bourgoin mechanism, the energy-release mechanism and some recoil mechanisms. Application of these mechanisms are discussed for crystalline and amorphous semiconductors, super-ionic materials and insulators in radiation damage, impurity and self-diffusion, ion-implantation, and dislocation-motion-experiments.

Enhanced diffusion mechanisms

Charge carrier drift velocities in semiconductor materials suitable for solid state detectors has been reviewed. Si, Ge, CdTe and GaAs are considered. New data for HgI2 recently obtained are also reported. The data cover a large range of temperatures (6-430 K) and electric fields up to 50 KV/cm. An anisotropy effect in the drift velocity obtained by applying the electric field parallel to different crystallographic axis is also discussed for the case of Si and Ge.

Charge Carrier Transport Properties of Semiconductor Materials Suitable for Nuclear Radiation Detectors

The average energy expended to create an electron-hole pair in silicon ?Si(T) has been measured in the 5-320°K temperature range with thin totally depleted surface barrier and diffused junction radiation detectors. The data have been normalized to a value of ?Si (300°K) = 3.62 eV. A dependence of ?Si on T much weaker than previously published by other authors has been observed. In the examined temperature range (5-320°K) our data are well fitted by ?si(T) = 2.15 Eg(T) + 1.21 eV where Eg(T) (in eV) is the value of the forbidden bandgap.

Measurements of the Average Energy Per Electron-Hole Pair Generation in Silicon between 5-320°K

Several experimental results are given on plasma time in solid state detectors. They were obtained by various kinds of ionizing particles (?-particles, deuterons and protons) incident on particular solid state detectors. These results refer to electric fields between 250 and 2500 V/cm and to temperatures of 300°K, 185°K and 77°K.

Plasma Time in Semiconductor Detectors

A pulsed electron accelerator has been built with the following characteristics: energy of the electrons up to 40 keV; average current up to 20 μA; minimum duration of each burst about 70 psec; frequency of repetition of the bursts up to 104 Hz; jitter of the burst with respect to a trigger pulse less than 80 psec; number of electrons per burst (current 5 μA, duration 0.2 nsec) 6.3×103; typical fluctuation on the number of electrons contained in a burst (FWHM) 1%. The accelerator consists of an electron source, made with an electron gun of type commonly used in video tubes, and two pairs of deflection plates perpendicular to each other. The electron beam passes through the plates and the duration of each burst is controlled by a sine wave applied to a pair of plates, while the repetition frequency is controlled by pulses of suitable width and amplitude on the other pair of plates. A pretrigger pulse is available. This accelerator was built to create, in a very short time, a large number of electron‐hole p...

A. Alberigi Quaranta

Papers

Drift velocity of electrons and holes and associated anisotropic effects in silicon

Charge Carrier Transport Properties of Semiconductor Materials Suitable for Nuclear Radiation Detectors

Measurements of the Average Energy Per Electron-Hole Pair Generation in Silicon between 5-320°K

Plasma Time in Semiconductor Detectors

A 40 keV Pulsed Electron Accelerator