| 摘要 |
PURPOSE:To prevent the occurrence of software errors due to alpha rays, by providing a first conducting type semiconductor layer, which is surrounded by an insulating film, between an embedded layer and a second semiconductor layer, and increasing resistance against external noises. CONSTITUTION:An N type embedded layer 2 is formed at the desire part in the surface region of a P type Si substrate 1. A P type doped layer 3 is formed by an ion implantation technology. Then, an epitaxial layer 4 is grown by a vapor phase epitaxy method. A silicon dioxide film 5 and a silicon nitride film 6 are formed on the layer 4. By using a selective oxidation method, a silicon dioxide region 7 for isolating elements is formed. The side of the P type doped layer 3 beneath an active region is surrounded by the silicon dioxide film 7. Then, a P type doped layer 8 and an N type doped layer 9 are provided. A potential can be applied from the surface of the substrate. Various devices are formed in the epitaxial layer from the substrate is effectively prevented. Occurrence of software errors due to alpha rays is avoided, and the extremely reliable device can be obtained. |
