Young & Thompson
Soi Substrate
 An SOI substrate comprises a silicon supporting substrate, an insulating film formed on the top of the silicon supporting substrate and a silicon active layer formed on the insulating film. The silicon supporting substrate is doped with an impurity at a concentration not less than 1.times.10.sup.17 atoms/cm.sup.3, provided that the impurity is kept in the solid solution state at a solidifying point of silicon. The impurity may comprise boron, phosphorus and arsenic. 
NEC Corporation
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additional inventional additional additional
Hiroaki
Kikuchi