Doping, of silicon

J. Guldberg, ed., Neutron-Transmutation-Doped Silicon, Proceedings of the Third International Conference on Transmutation Doping of Silicon, Copenhagen, Denmark, Plenum Press, Inc., New York, 1981. 

The addition of a trivalent atom (e.g. boron) to silicon leads to an empty electron state, or positive hole, which can be ionized from the effective single negative charge — e on the B atom. The ionization energy is again about 0.01 eV, as might be expected. Therefore the doping of silicon with boron leads to the... 

Doerk GS, Festari G, Liu F, Carraro C, Maboudian R (2010) Ex situ vapor phase boron doping of silicon nanowires using BBrs. Nanoscale 2 1165-1170... 

The doping of silicon with boron to an atomic concentration of 0.0010% boron atoms vs. silicon atoms increases its conductivity by a factor of 10 at room temperature. How many atoms of boron would be needed to dope 12.5 g of silicon What mass of boron is this ... 

Ionization chambers (W) for implantation of ions in the doping of silicon wafers. 

FIGURE 18.7 Doping of silicon in semiconducting devices. Adding atoms with five vaience electrons (e.g., arsenic) introduces extra electrons that can move through the crystal. Adding atoms with three valence electrons introduces holes that can also move through the crystal. Note that each silicon atom has four valence electrons, so a perfect crystal has each silicon atom surrounded by an octet of electrons. 

Silicon alloyed with a copper catalyst and promoter substances reacts with methyl chloride (at temperatures around 300 °C) to give a mixture of methylchlorosilanes in the industrial direct synthesis. Dimethyldichlorosilane represents the most important target in this process. Since Rochow [1] and Mtiller [2] discovered this direct synthesis route for the silicon-promoter-catalyst system, many investigations were done to increase the activity as well as the selectivity and to clarify the mechanism. Zinc, tin, and phosphorus, beside other substances, were found to give effects [3-6]. The goal of this research work is to find out whether there are relationships between the electronic effect of phosphorus, tin, boron, or indium doping of silicon and its reactivity as well as selectivity in direct synthesis. Characterization of the electronic state of the variously doped silicon relies on photo-EMF measurements. 

A number of modifications to the etching process are possible, e.g. heavy doping of silicon by boron (10 atoms cm ) acts as an effective barrier to stop the etching process in ethylene-diamine and pyrocatechol-based etchants. 

Fig. 1.4 A1 doping of silicon effects the formation of a vacancy in the electronic shell (see arrow tip). The arrow indicates that this results in electronic (hole) conductivity. The electron hole migrates in the opposite direction.

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