A semiconductor device includes a substrate including a first region and a second region, a trench-gate transistor in the first region, the trench-gate transistor including a first trench in the substrate, a gate filling at least part of the first trench, and a source in the substrate and on each sidewall of the first trench, a first field diffusion junction in the second region, an interlayer insulating film on the substrate, the interlayer insulating film covering the trench-gate transistor and the first field diffusion junction, a first contact in the first region, the first contact passing through the interlayer insulating film and contacting the source, and a second contact in the second region, the second contact passing through the interlayer insulating film and contacting the first field diffusion junction, the first contact and the second contact having an equal height and including a same material.