Esd structure

Abstract

Electrostatic discharge (ESD) structures are provided. An ESD structure includes a semiconductor substrate, a first epitaxy region with a first type of conductivity over the semiconductor substrate, a second epitaxy region with a second type of conductivity over the semiconductor substrate, and a plurality of semiconductor layers. The semiconductor layers are stacked over the semiconductor substrate and between the first and second epitaxy regions. A first conductive feature is formed over the first epitaxy region and outside an oxide diffusion region. A second conductive feature is formed over the second epitaxy region and outside the oxide diffusion region. A third conductive feature is formed over the first epitaxy region and within the oxide diffusion region. A fourth conductive feature is formed over the second epitaxy region and within the oxide diffusion region. The oxide diffusion region is disposed between the first and second conductive features.