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A novel silicon-on-insulator (SOI) high-voltage device structure and its eliminating back-gate bias effects are described and the structure is characterized by a compound buried layer (CBL) made of two layers and a polysilicon layer between them. The maximal temperature of CBL SOI is reduced by 25 K because of a window in upper buried oxide (UBO) when compared with the conventional SOI.

222Rn and 220Rn concentrations were measured in cave dwellings and brick houses in the region of Yan'an (China) during summer 1997. The underground dwellings are built into Quaternary loess, and all investigated houses are founded on it. The median values of indoor 222Rn and 220Rn concentrations are42 (n = 18) and 77 Bq m-3 (n = 15) for brick houses and 92 (n = 23) and 215 (n = 17) Bq m-3 for cave dwellings. To classify the dwellings in respect to their 'cave-character,' the fraction of walls having a direct contact to the loess is calculated for each dwelling. While the 222Rn concentrations are increasing with higher fractions, the 220Rn concentrations are notcorrelated with this fraction. On the other hand, due to the short half-life of 220Rn the distance from the measuring point tothe walls is negatively correlated with the 220Rn concentration, while there is no correlation with the 222Rn concentration. Therefore, concentric isolines of 220Rn concentrations showing a strong gradient were detected in cave dwellings. An influence of the ventilation rate is distinct for 222Rn but weak for 220Rn. The effective dose rates for 222Rn and 220Rn and their progenies are calculated for brick houses (2.7 mSv y-1), cave dwellings (7.1 mSv y-1), and for traditional cave dwellings with a bed foundation built with loess (16.7 mSv y-1). These calculations are based on summer measurements only. It is expected that the true effective dose rates will be significantly higher. [ABSTRACT FROM AUTHOR]