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Please follow the links to view the publication.The state of etched semiconductor surfaces as revealed by electron diffraction
http://dl-live.theiet.org/content/journals/10.1049/pi-b-2.1959.0071
Germanium and silicon (100) and (111) surfaces have been etched with a variety of reagents and subsequently examined by reflection electron diffraction. No oxide layers were detected on surfaces etched with the common mixtures containing hydrofluoric and nitric acids. When metal ions were present, either as essential components or as impurities in the etchants, deposits, either of the metals or of compounds, were sometimes found; in particular, contamination from materials commonly used for making contacts to devices has been found. No preferential deposition was found on either side of an etched <i xmlns="http://pub2web.metastore.ingenta.com/ns/">p-n</i> junction.Details of the sensitivity of electron diffraction are included as an Appendix.Some effects of pulse irradiation on semiconductor devices
http://dl-live.theiet.org/content/journals/10.1049/pi-b-2.1959.0082
The effects of pulse irradiation upon majority and minority carrier properties of semiconductor devices are presented, with emphasis on those effects peculiar to radiation rates of the orderof 10<sup xmlns="http://pub2web.metastore.ingenta.com/ns/">16</sup> neutrons/cm<sup xmlns="http://pub2web.metastore.ingenta.com/ns/">2</sup> per second and 10<sup xmlns="http://pub2web.metastore.ingenta.com/ns/">7</sup> röntgens (γ)/sec. Experimental data and semiconductor theory are employed to obtain expression for the dependence of device parameters on integrated neutron exposure in germanium and silicon. Comparisons are made of the effects produced by neutrons and γ-rays. Experimental data for the transient photo-voltaic effect observed in junction devices under pulse irradiation are discussed on the basis of current theory.The growing of 5 kg single crystals of germanium
http://dl-live.theiet.org/content/journals/10.1049/pi-b-2.1959.0161
Consideration of the factors involved in the efficient production of semiconductor devices reveals the desirability of growing large single crystals of germanium. The technical specification for the material demands that this shall not be achieved at the expense of quality, i.e. the germanium must be of the correct resistivity, lifetime and dislocation density. The realization of the potential advantages has involved the solution of a range of problems.In pulling large crystals the growth must be precisely controlled to give the level interface conditions and thermal gradients associated with good crystal perfection and uniform transverse properties.A high-vacuum radiation-heated furnace is used in which the heaterbaffle assembly is fabricated from high-purity graphite, silica and molybdenum. In this assembly the mechanical construction, the heater and the disposition of the baffle system need careful design to obtain the necessary high-temperature rigidity and the correct heat field over the area involved. (The Crucible internal diameter is 150 mm.) Both stationary and rotating crucible systems have been successfully used, the rotating type having several advantages.Melt preparation demands a high standard of chemical cleanliness, and this is more difficult to attain with large quantities than with small quantities of material. A technique has been developed based on a potassium-hydroxide/hydrogen-peroxide etch which is both safe and completely satisfactory chemically.The dark-spot method for measuring the diffusion constant and length of excess charge carriers in semiconductors
http://dl-live.theiet.org/content/journals/10.1049/pi-b-2.1959.0075
The well-known basic method of measuring diffusion length, introduced by Goucher, is here applied in its optimum form. This consists illuminating the semiconductor surface with interrupted light of uniform intensity and casting a circular shadow whose diameter can be varied. A detector is placed at the centre of the shadow and the variation of signal with the shadow radius can be interpreted theoretically with high precision. The method possesses advantages of circular symmetry, maximum signal strength, simplicity of optical apparatus, and speed of operation. The same apparatus may be employed to measure the diffusion coefficient by using repeated impulses of light, the results giving an exponential law independent of surface recombination.Full experimental details and discussions are given, together with complete mathematical theory which takes into account surface recombination, penetration of photons, boundary effects and shadow effects, and gives a method of measuring the rate of change of diffusion length across the sample surface. A number of experimental results are presented with a tabulated function for their interpretation.Some fundamental aspects of <i xmlns="http://pub2web.metastore.ingenta.com/ns/">p-n</i> junctions
http://dl-live.theiet.org/content/journals/10.1049/pi-b-2.1959.0081
It is pointed out that in many practical <i xmlns="http://pub2web.metastore.ingenta.com/ns/">p-n</i> junctions the internal field strengths and dimensions are such that the diffusion equation for the current which is commonly applied is seriously in error. In consequence, it is suggested that no valid analysis has yet been made of <i xmlns="http://pub2web.metastore.ingenta.com/ns/">p-n</i> junction characteristics, and that a major advance in statistical theory is necessary before this becomes possible.It is also suggested that it is to be expected that there will be a significant difference between germanium and silicon junction devices in their characteristic-material relationships.