Abstract
Semiconductor device structures and methods for manufacturing the same are provided. The semiconductor device structure includes a substrate, a first nitride semiconductor layer, a second nitride semiconductor layer, a gate structure, a first spacer, a second spacer and a drain electrode. The first nitride semiconductor layer is disposed on the substrate. The second nitride semiconductor layer is disposed on the first nitride semiconductor layer. The gate structure is disposed on the second nitride semiconductor layer. The first spacer is disposed adjacent to a first surface of the gate structure. The second spacer is disposed adjacent to a second surface of the gate structure. The drain electrode is disposed relatively adjacent to the second spacer than the first space. The first spacer has a first length, and the second spacer has a second length greater than the first length along the first direction.