| 摘要 |
PURPOSE:To increase withstanding voltage between elements by each forming an oxide film with a window for shaping a buried layer to the surface of a semiconductor substrate and an oxide film with a window for aligning a mask in an isolation region to the back and forming an isolation layer for isolating the buried layer and a buried layer by using these oxide films. CONSTITUTION:An oxide film 2 with windows 3 for shaping two buried layers is formed onto the surface of a P type Si substrate 1 and an oxide film 15 with windows 16 for aligning a mask to an isolation region for isolating two buried layers onto the back respectively. N type impurity ions are implanted into two windows 3 to form N<+> type buried regions 4a, 4b, an oxide film 5 consisting of the film 2 in which thin oxide films are shaped in the windows 3 is removed, and an N type layer 6 is grown on the whole surface containing the regions 4a and 4b in an epitaxial manner. An oxide film 7 with three windows 8 is formed onto the layer 6 while using an oxide film 17 composed of the residual film 15 as a mark, a P type impurity is diffused into the windows until it intrudes into the substrate 1, and the regions 4a and 4b are isolated by a P<+> type isolation region 9 shaped. |
