No abstract

We found octahedral void defects in the bulk of silicon wafers by using infrared tomography. These voids are often twin type and their sizes are about 100 nm. A 2-nm-thick layer exists on the side walls of the void defects. Our analysis suggests that the 2-nm-thick layer is SiOx. It is believed that the void structure is formed as a result of agglomeration of vacancies during Si–ingot growth.

No abstract

Some preliminary results on the comparison of scintillation efficiencies of scintillators based on two white oils are described. It is shown that a new solvent, technical white oil, has a better scintillation efficiency than that of medicinal paraffin, A possible reason for this higher efficiency is discussed.

We examined the effect of thermal annealing in vacuum on the behavior of dual-type octahedral void defects in Czochralski silicon. We found that the smaller void shrinks first at about 1100°C and that during the shrinkage of the smaller void to extinction, the bigger void maintains its structure and size. In addition, we found that shrinkage of the smaller void begins from the adjacent region between the two voids. We believe that the effect of minimizing the surface energy first takes place selectively in the smaller void and that after the extinction of the smaller void, the effect of minimizing the surface energy takes place in the bigger void.