The dielectric separable substrate production manner null of the semiconductor device and the dielectric separable substrate which use

摘要

PURPOSE:To decrease the number of trenches occupying comparatively large areas, and to increase an element forming area by forming element isolating trench sections insularly isolating a second silicon wafer and a silicon layer and element isolating insulating films shaped onto the side faces of the trench sections or buried and formed in the trench sections. CONSTITUTION:A second silicon wafer (a wafer for shaping an element) 102 as a p- active layer is bonded onto a wafer 101 through an oxide film (an insulating film) 103. The bonding is realized in such a manner that each surface of two silicon wafers 101, 102 is mirror-polished, the oxide film is formed to at least one of ground surfaces, and these surfaces are superposed. An n- epitaxial layer 104 is grown on the p- active layer 102', and a V trench 105 is shaped to these each layer 102', 104. An oxide film 106 is formed onto the side face of the V trench 105, and the V trench 105 is buried with a polycrystalline silicon film 107. A MOS element and a bipolar element, etc., are formed to the n- epitaxial layer 104.