| 摘要 |
PURPOSE:To make utilization efficiency high in a chip by a method wherein, in a protective circuit element which is fabricated in the common process as other internal circuit elements, a terminal for checking characteristic is provided and diagnosis of internal circuit may be performed by checking the protective circuit element. CONSTITUTION:A field oxide film 12 is formed on the surface of an n-type Si substrate 10, and an MOSFETQ which is a part of an internal circuit is formed on the surface of the substrate within the first opening of an oxide film 12, and a protective doide D is formed on the surface of the substrate within the second opening of the oxide film 12, and a protective resistance layer R is formed on the oxide film 12. And to diagnose characteristic of an internal circuit including the MOSFETQ, resistance value, junction leakage etc. can be checked easily by checking time constant of RC circuit which consists of a resistance layer 18 (R) and a diffused layer 24 of a diode D. Thus provision of any special dummy element is not necessary and efficiency of utilization is improved. |
