| 摘要 |
PURPOSE:To prevent the hot carrier effect and the breakdown strength of gate oxide film from deteriorating without fail even if a semiconductor device is miniaturized by a method wherein a gate oxide film of MOSFET in an input.output circuit actuated by externally fed power supply voltage is formed thicker than another gate oxide film of MOSFET in an inner circuit actuated by a power supply voltage lowering circuit 13. CONSTITUTION:A gate oxide film 19 of an MOSFET comprising an input.output circuit part 12 is formed thicker than another gate oxide film 18 of another MOSFET comprising a cell and ambient circuit 14. In such a constitution, the MOSFET comprising the input.output circuit part 12 with thick gate oxide film can prevent the hot carrier effect and the breakdown strength of gate oxide film from deteriorating likewise the cell and ambient circuit 14 can prevent the hot carrier effect and the breakdown strength of gate oxide film from deteriorating to notably improve the reliability of MOSFET of overall circuit comprising an LSI chip 11. |
