Effect Of Impurity Concentration Research Articles

FREEZE-OUT CHARACTERISTICS OF THE MOS VARACTOR

Experimental MOS C(V) data are obtained in the temperature range over which majority carriers are substantially frozen out (40° − 70°K). These are compared with calculated curves and other calculated curves are presented to show the effect of impurity concentration and compensation. The C(V) curves are characterized by a secondary minimum in capacitance near the flat band bias.

Analytical representations of solid-state devices

Simple expressions for the dependence of hole and electron mobilities upon free carrier densities are utilized to derive equivalent representations of the diode equation as well as other solid-state device equations. The resulting mathematical models vividly display the effects of impurity concentrations in the semiconductor regions on important device parameters.

Self-diffusion in naphthalene single crystals

Abstract Studies of self-diffusion in pure single crystals of naphthalene have been carried out by a sectioning method, using a 14C labelled tracer. The effects of impurity content and pre-annealing upon the diffusion process “were examined. Diffusion coefficients are low compared to those found for other solid systems. In the best available crystals self-diffusion can be described by an equation D = 2·5×1015 exp (−(42·7×1·6 kcal mole−1) RT)cm2.sec−1. The self-diffusion process probably represents diffusion via a vacancy mechanism. Because of the low values of the diffusion coefficient, diffusion may be modulated by the presence of dislocations in the crystal lattice.

THERMALLY ACTIVATED DEFORMATION OF α TITANIUM BELOW 0.4 TM

The effects of temperature, strain rate, and purity on the yield and flow stresses of α titanium at low temperatures (T < 0.4 TM) are examined to ascertain the rate controlling dislocation mechanism. The effect of impurity content on the thermal component of the yield and flow stresses increases with the decrease in temperature to 0 °K. The activation volume for the plastic flow of titanium of commercial purity ranges from 80b3 at τ* = 1 kg/mm2 to 8b3 at τ* = 45 kg/mm2. The activation energy ranges from about 1.3 eV to 0.18 eV over the same stress range. The experimental data are in good accord with the thermally activated overcoming of interstitial atoms as the rate controlling mechanism and a linear force-distance curve with FM = 43.2 × 10−6 dynes (0.9 × 10−1 μb2), d0 = 3.25b, and H0 = 1.25 eV (0.21 μb3).

The effect of impurity content and heat treatment on theR 273/R 78 resistivity ratio of aluminium and copper

The effect of impurity content and heat treatment on theR 273/R 78 resistivity ratio of aluminium and copper

Principles of p-n Junction Detectors

Elementary band theory and impurity concentration effects are reviewed in order to derive the basic relations for barrier layer width and electrostatic potential as a function of applied reverse bias. Use of the solid-state ionization detector in the laboratory curriculum is indicated with sample lab experiments.

帯域熔融精製した錫及び鉛の下部組織の顕微鏡観察

The following findings are obtained by microscopic observation of the substructure in the zone-refined lead and tin. (1) The corrugation structure is observed only at the impure tail part of zone-refined bar. Coming nearer to the tail part, corresponding to the increase of impurity content, corrugation once appears and then disappears, this is repeated two or three times, and thereafter continuous corrugation takes place. (2) The effect of impurity concentration on the width of corrugation is rather complicated, sometimes widening and sometimes narrowing it down. As a general tendency, with the increase of impurity content the width of corrugation increases and after passing over a maximum value it continues to decrease till the appearance of dendritic growth. (3) Striation is observed in all parts of the bar, and it is not sensitive to the impurity content. (4) The striation boundaries are linear arrays of etch pits, possibly due to edge dislocations. (5) Banding does not coexist with corrugation structure and is observed only in portions of higher purity.

Concentration Effects on the Line Spectra of Bound Holes in Silicon

The effect of impurity concentration on the line spectra of holes bound to B, Al, and Ga acceptors in silicon has been studied at 21\ifmmode^\circ\else\textdegree\fi{}K. Details of the spectra (i.e., relative positions, line shapes, intensities) differ for the different acceptors. Below an acceptor concentration of about ${10}^{16}$/${\mathrm{cm}}^{3}$ the spectra are concentration-independent under the conditions of measurement. Above ${10}^{16}$/${\mathrm{cm}}^{3}$ the spectral lines begin to broaden and by \ensuremath{\sim}${10}^{18}$/${\mathrm{cm}}^{3}$ the line structure has been almost completely destroyed. A qualititive discussion of the concentration effects is given.