| 摘要 |
An apparatus comprises a substrate, a first buried layer formed over the substrate, the first buried layer comprising one or more raised mesa structures, a second buried layer formed over the first buried layer, an active layer formed over the second buried layer, and a capping layer formed over the active layer. The apparatus may further comprise a third buried layer formed over the active layer, the third buried layer comprising one or more raised mesa structures, and a fourth buried layer formed over the third buried layer. The one or more raised mesa structures of the first buried layer may be offset from the one or more raised mesa structures of the third buried layer. |
