| 摘要 |
<p>A semiconductor device comprises a substrate (30), a compound semiconductor layer (34) provided on the substrate, and an active region (34a - 34c) formed on the compound semiconductor layer. The substrate in turn comprises a first semiconductor layer (31) of a first semiconductor material, a second semiconductor layer (32a, 32b) of a second semiconductor material and provided on the first semiconductor layer, and a third semiconductor layer (33, 33A) provided on the second semiconductor layer, wherein the third semiconductor layer comprises a plurality of segments (x, y) each defined by a pair of side walls that extend substantially perpendicular to the third semiconductor layer. The plurality of segments comprises a plurality of first-type segments (x) and a plurality of second-type segments (y) wherein the first- and second-type segments are arranged alternately when viewed in a direction parallel to the third semiconductor layer. The first- and second-type segments have respective lattice constants that differ with each other such that a stress field acting substantially perpendicular to the third semiconductor layer is induced in the third semiconductor layer.</p> |
