The invention provides an
LDMOS-SCR device with a source-end embedded finger NMOS, which can be applied to improving ESD protection reliability of an on-
chip IC. The
LDMOS-SCR device with the source-end embedded finger NMOS mainly comprises a P substrate, a P
epitaxy, a P well, an N well, a first N+ injection region, a second N+ injection region, a first P+ injection region, a third N+ injection region, a fourth N+ injection region, a second P+ injection region, a fifth N+ injection region, a plurality of polysilicon gates, a plurality of thin gate oxides and a plurality of
field oxide insulation regions. On one hand, the second P+ injection region, a third
polysilicon gate, the fifth N+ injection region, the N well, the P well, the first P+ injection region, the first N+ injection region form a parasitical
LDMOS-SCR current path, thereby reinforcing the ESD robustness of the LDMOS-SCR device; on the other hand, the first N+ injection region, a first
polysilicon gate, a first
thin gate oxide, the second N+ injection region, the first P+ injection region, the third N+ injection region, a second
polysilicon gate, a second
thin gate oxide and the fourth N+ injection region form the finger NMOS and a parasitic
resistor, thereby forming a resistance-
capacitance coupling effect; thereby, the maintaining
voltage is increased.