Abstract: A semiconductor device is provided, which includes an epitaxial structure, a first contact electrode and a second contact electrode. The epitaxial structure includes a first semiconductor structure, a second semiconductor structure and an active region. The first semiconductor structure includes a first semiconductor contact layer. The second semiconductor structure includes a second semiconductor contact layer. The active region is located between the first semiconductor structure and the second semiconductor structure. The first contact electrode is located on the second semiconductor contact layer and directly contacts the first semiconductor contact layer. The second contact electrode is located on the second semiconductor contact layer and directly contacts the second semiconductor contact layer. The first semiconductor contact layer has a conductivity type of n-type and includes a first group III-V semiconductor material.

Abstract: A semiconductor device is provided, which includes an epitaxial structure, an electrode pad, and a contact region. The epitaxial structure includes a geometric center, a first surface and a second surface opposite to the first surface. The electrode pad is on the first surface. The contact region is on the second surface and includes a first group and a second group. The first group includes a plurality of first contact portions separated from each other and is arranged in a first ring shape. The second group includes a plurality of second contact portions separated from each other and is arranged in a second ring shape. A second distance between each of the plurality of second contact portions and the geometric center is greater than a first distance between each of the plurality of first contact portions and the geometric center.