US Patent 7667280 Semiconductor device

Provided is a semiconductor device having a trench isolation structure and a high power supply voltage circuit section including at least a well region and a MOS transistor formed therein. The high power supply voltage circuit section includes a carrier capture region for preventing latch-up in a vicinity of an end portion of the well region, and a depth of the carrier capture region is larger than a depth of the trench isolation region. The carrier capture region in the high power supply voltage circuit section is formed of a diffusion layer which is the same as that of a source or a drain region of the MOS transistor formed in the high power supply voltage circuit section.