| 摘要 |
PURPOSE:To obtain a separated dielectric substrate having a high withstand voltage by a simple process when a semiconductor substrate is to be made in an island shape by V-shaped separating slots by a method wherein a lamination structure consisted of a high impurity concentraton region and an insulating oxide film are prepared under the base of island region. CONSTITUTION:An n-type Si substrate 31 is covered with an SiO2 film 32 and is etched using an anisotropic etching liquid, and V-shaped separating slots 33 are formed to produces an island region in the substrate 31. An n-type impurity is made to diffuses into the whole face containing the slots 33 to form an n<+>-type region 34 constituting a channel stopper in the surface layer of substrate 31 under the film 32, and the whole face is covered with an insulating SiO2 film 32. Then a polycrystalline Si layer 35 is piled up having the thickness deeper than the slots 33 being able to withstand handing, the back face of substrate 31 is burnished to expose the apex of slots 33 and the region of substrate surrounded with slots 33 is made to be a complete island-shape. After the disposition mentioned above, each function element 38, Al wirings 39, etc., are prepared in a single crystalline island 36 by an ordinary method. |
