US Patent 9997510 Semiconductor device layout structure

The invention provides a semiconductor device layout structure disposed in an active region. The semiconductor device layout structure includes a first well region having a first conduction type. A second well region having a second conduction type opposite the first conduction type is disposed adjacent to and enclosing the first well region. A first doped region having the second conduction type is disposed within the first well region. A second doped region having the second conduction type is disposed within the first well region. The second doped region is separated from and surrounds the first doped region. A third doped region having the second conduction type is disposed within the second well region.