| 摘要 |
PURPOSE:To improve the latchup withstand of a semiconductor device by forming a well region on a part of an epitaxial substrate, and forming an N- channel MOS transistor therein and a P-channel transistor at the position separated therefrom to construct a CMOS inverter. CONSTITUTION:A P-well region 7 is formed on an N-type epitaxial substrate 1, N-type source and drain regions 9, 11 are formed therein as an N-channel MOS transistor 3, P-type drain and source regions 19, 21 are formed in the portion that no region 7 exists as a P-channel MOS transistor 5, thereby forming MOS inverter. In this structure, the thickness of the substrate 1 is approx. 4mum, a trench deeper than 2mum is opened between the transistors 3 and 5, semiconductor substance enclosed by an oxide film is buried to separate the transistors 3, 5. Thus, a voltage for holding the latchup state of a parasitic thyristor can be applied. |
