Semiconductor device with ESD protective circuit

Abstract

A semiconductor device with an electrostatic discharge (ESD) protective circuit is disclosed. In this semiconductor device with an ESD protective circuit, an n-well guard ring is formed around an NMOS field transistor of a data input buffer or around an NMOS transistor of a data output buffer. The n-well guard ring is strapped to an n-well of a PMOS field transistor and to an n-well of a PMOS transistor, and thus a PNPN path is formed toward the PMOS transistor at a positive mode of the ground voltage. Therefore, the electrical resistance between the wells of the NMOS transistors and the PMOS transistors can be reduced, thereby improving the characteristics of the ESD protective circuit and a latch-up device. Further the layout area is reduced, and thus, the characteristics and the reliability of the semiconductor device are improved.

Dependencies are inferred from the claim text.