Search

Some remarks are made about the agreement between the experimental results and the theoretical model of Neumark. It is believed that the presence of an impurity band and of localized tail states is not sufficiently accounted for.

Sub-microsecond excess carrier lifetimes have been measured by a contactless method and the electrical properties have been investigated by the isothermal capacitance method in heat-treated N-type silicon. It is found that the thermally induced donor level at E v +0.39 eV acts as recombination center. By using the present contactless measurement system, it becomes possible to accurately measure lifetimes as short as 0.07 µsec, and resistivity-lifetime products, ρτ=0.1 Ωcm · µsec, have been achieved.

Gold was in-diffused into n-type silicon single crystals at 800-1150°C. DLTS spectra of the Schottky diode of the specimen were measured and four peaks (E c-0.16, E c-0.24, E c-0.30 and E c-0.54 eV) were observed. As the gold concentration and the gold-diffusion temperature increased, the relative height of the peak of E c-0.24 eV increased compared to the most prominent peak of E c-0.54 eV. The concentration of the peak of E c-0.30 eV was saturated at about (1-4)×1014 cm-3.

A characteristic deep level (E4 trap) is observed only by high-temperature thermal oxidation of CZ silicon and cannot be detected in nitrogen ambient annealing. The E4 trap concentration depends on the position in the wafer. Depth profiles of the E4 trap concentrations vary remarkably with the cooling time. These facts suggest that the E4 deep level originates in the silicon self-interstitial related to the grown-in defects.

F.M.-noise measurements on p-type, step-abrupt n-type and uniformly doped n-type silicon IMPATT-diode oscillators show the correlation between the width of the avalanche zone and f.m. noise. A reduction in the f.m.-noise parameter and an increase in the d.c.-to-r.f.-conversion efficiency have been observed for IMPATT devices with a thinner effective avalanche zone.

The non-equilibrium minority carriers produced by the α-particles while penetrating into the diffused layer of the Au-Si surface barrier detector diffuse into the boundary of barrier layer and are then collected. Hence an output pulse is obtained at the two terminals of the detector. The collecting efficiency in the diffused layer and the relations between the collecting efficiency and the diffusion length are calculated. The experimental results have been compared with the theory, and the diffusion length of minorty carriers is then determined.

Using radiotracer methods, a study has been made of the increased gold solubility in uniformly heavily n‐doped silicon. Data for both phosphorus and arsenic showing gold solubility as a function of doping is presented. The gold solubility at 1000°C begins to increase substantially for concentrations of donor impurity in the range 1019 cm−3, although a difference in this increase between arsenic doping and phosphorus doping was noted. The data was related quantitatively to an ion pairing model which appeared to best explain the results.