A semiconductor device and a manufacturing method for the same are provided. The semiconductor device comprises a first doped region, a second doped region, a dielectric structure and a gate structure. The first doped region has a first type conductivity. The second doped region has a second type conductivity opposite to the first type conductivity and is adjacent to the first doped region. The dielectric structure comprises a first dielectric portion and a second dielectric portion separated from each other. The dielectric structure is formed on the first doped region. The gate structure is on a part of the first doped region or second doped region adjacent to the first dielectric portion.