Semiconductor device

A semiconductor device comprising:

• a semiconductor structure including a first conductive type semiconductor layer, a second conductive type semiconductor layer, and an active layer disposed between the first conductive type semiconductor layer and the second conductive type semiconductor layer;
• a first electrode electrically connected to the first conductive type semiconductor layer;
• a second electrode electrically connected to the second conductive type semiconductor layer;
• and
• a reflective layer disposed below the second electrode,
• wherein the second conductive type semiconductor layer includes a first sub-layer and a second sub-layer that is disposed between the first sub-layer and the active layer and has an aluminum (Al) composition higher than an Al composition of the first sub-layer,
• the reflective layer is in contact with a bottom surface of the second sub-layer, and
• the second electrode is in contact with the first sub-layer,
• wherein
• a ratio of an area of the first sub-layer and an area of the second sub-layer is in a range of 1:1.01 to 1:1.5,
• a ratio of an area of the first electrode and an area of the second electrode is in a range of 1:3.88 to 1:5.8, and
• a ratio of an area of the reflective layer and the area of the second electrode is in a range of 1:2.4 to 1:3.6.