| 摘要 |
PURPOSE:To obtain a material of a high-integration degree insulating isolation structure for the use of the substrate of a semiconductor device by a method wherein a columnar single crystal semiconductor region, whose surface and back surface have been exposed, is formed and semiconductor regions are respectively formed insularly on the polycrystalline semiconductor region through an insulating film. CONSTITUTION:A single crystal Si substrate 5 is etched, a hill 6 is formed on the central part of the substrate 5, the whole surface is covered with a polycrystalline Si layer 8 through an insulating film 7, the surface of the polycrystalline Si layer 8 is polished and the top surface 9 of the hill 6 is made to be exposed. Semispherical etching grooves 10 are provided in the lower surface of the substrate 5, a hill 6' is formed corresponding to the mountain 6 and one columnar layer is completed. Further, the insulating films 7 are respectively exposed on the bottom surfaces 11 of the etching grooves 10, and the polycrystalline Si layers 8 are respectively deposited thicker through insulating films 7'. Lastly, the back surface of the substrate 5 is polished to enable to expose both of the Si layer 6' and two Si layers 12, and a material for the substrate of a semiconductor device is completed. According to this constitution, a substrate; which has a high-integration density isolation structure, and also, has a columnar layer, whose surface and back surface have been exposed and which is indispensable for a high- withstand voltage semiconductor device, and Si islands, which have been insulatingly isolated and have been formed in the manner of insularly floating on a polycrystalline layer; can be obtained. |
