BONDED SOI WAFER MANUFACTURING METHOD

摘要

The present invention is a method for manufacturing a bonded SOI wafer by bonding a bond wafer and a base wafer, each composed of a silicon single crystal, via an insulator film, including the steps of: depositing a polycrystalline silicon layer on the bonding surface side of the base wafer, polishing a surface of the polycrystalline silicon layer, forming the insulator film on the bonding surface of the bond wafer, bonding the polished surface of the polycrystalline silicon layer of the base wafer and the bond wafer via the insulator film, and thinning the bonded bond wafer to form an SOI layer; wherein, as the base wafer, a wafer having a resistivity of 100 ©·cm or more is used, the step for depositing the polycrystalline silicon layer further includes a stage for previously forming an oxide film on the surface of the base wafer on which the polycrystalline silicon layer is deposited, and the polycrystalline silicon layer is deposited by two stages including a first growth performed at a first temperature of 1010°C or less and a second growth performed at a second temperature being higher than the first temperature to deposit the same thicker than in the first growth. As a result, it is possible to provide a method for manufacturing a bonded SOI wafer which can prevent single-crystallization of polycrystalline silicon while suppressing an increase of the warpage of a base wafer even when the polycrystalline silicon layer to function as a carrier trap layer is deposited sufficiently thick.