Soi wafer and its manufacturing method

摘要

Since a supporting wafer contains boron of 9x10¹⁸ atoms/cm³ or more, therefore a part of the metal impurities in an active layer wafer and the metal impurities in the wafer can be captured by the boron during the heat treatment for bonding. As a result, metal contamination in the active layer can be reduced. Moreover, the wafer strength is enhanced, thus preventing the wafer slipping. Since the wafer has no COP, micro voids are not detected in the LPD evaluation of the active layer, thereby improving the reliability of the evaluation. Such a bonded wafer can be manufactured at a low cast.