| 摘要 |
PURPOSE:To easily extract a substrate voltage from the surface of device having the structure where elements are isolated by grooves by forming a diffused layer in the same conductivity type as the substrate in such a depth as it reaches the substrate on the substrate voltage extracting region. CONSTITUTION:A resist film or oxide film 33 is formed on a P type semiconductor substrate 31 and then it is patterned. Thereafter, an N<+> type buried diffused layer 32 is formed by implanting the N type impurity. After removing the film 33, the N type epitaxial layer 34 is formed by the epitaxial growth method. A U-groove 37 for element isolation is formed and the resist film 34 is patterned. A P<+> type diffused layer 36 is formed by implanting the P type impurity. The layer 36 is as deep as it reaches the substrate 31 through the layer 34. With such a structure, the terminal chip and wire bonding are no longer necessary and a substrate voltage can easily be extracted from the device surface. |
