| 摘要 |
PURPOSE:To prevent the occurrence of bending in a substrate during the process of fabrication of elements by a method wherein a polycrystalline Si layer, a single crystal Si layer, and a polycrystalline Si layer are laminated and piled on an Si single crystal substrate on which a dielectric film is provided, and the uppermost polycrystalline Si layer is made thin by grinding it. CONSTITUTION:An Si single crystal substrate 1, on which separation mechanism 2 is provided and whose entire surface, including this, is coated with an SiO2 film 3, which is a dielectric film, is formed a support region consisting of polycrystalline Si layers 4a-4h, which are separated by films 5 and form a laminate of alternate polycrystalline Si layers 4 and SiO2 films 5. At this time, the layers up to the 8th, counted from film 3... layers 4a-4h... are made thicker compared with the remaining layers...layers 4i-4k, and the last layer 4k is made thinner by grinding it. By this, even if an impurity is diffused into regions 1a-1c of substrate 1 in an atmosphere containing O2, since layers 4i-4k are thin, practically no bending occurs in substrate 1. |
