Nitride semiconductor laser device and method of producing the same
View Patent ↗A nitride semiconductor laser device has a semiconductor multi-layer structure that includes a lower clad layer of a first conductive type, an active layer, and an upper clad layer of a second conductive type stacked in this order on a substrate, wherein a layer under the active layer includes a stripe-like trench; the semiconductor multi-layer structure includes a stripe-like optical cavity arranged along the stripe-like trench; the stripe-like trench has a narrower width in its both end regions compared to its central main region; and the active layer is formed of a nitride semiconductor containing In.
1. A nitride semiconductor laser device comprising a semiconductor multi-layer structure including at least a lower clad layer of a first conductive type, an active layer, and an upper clad layer of a second conductive type stacked in this order on a substrate, wherein
a layer under said active layer includes a stripe-like trench;
said semiconductor multi-layer structure includes a stripe-like optical cavity arranged along said stripe-like trench;
said stripe-like trench has a narrower width in its both end regions as compared with its central main region; and
said active layer is formed of a nitride semiconductor containing In.
2. The nitride semiconductor laser device according to claim 1 , wherein said active layer has a less In concentration in the narrower end regions of said stripe-like trench than in the central main region.
3. The nitride semiconductor laser device according to claim 2 , wherein said active layer has a greater energy band gap in the narrower end regions of said stripe-like trench than in the central main region.
4. The nitride semiconductor laser device according to claim 2 , wherein said active layer has a smaller thickness in the narrower end regions of said stripe-like trench than in the central main region.
5. A method of producing the nitride semiconductor laser device of claim 1 , comprising:
forming said stripe-like trench including alternate wide-width regions and narrow-width regions on said substrate by etching;
depositing said lower clad layer of the first conductive type, said active layer, and said upper clad layer of the second conductive type in this order on said substrate;
conducting cleavage across each of said narrow-width regions of said stripe-like trench; and
conducting chip segmentation for each of said stripe-like optical cavity.
6. A method of producing the nitride semiconductor laser device of claim 1 , comprising:
depositing up to said lower clad layer of the first conductive type on said substrate,
forming said stripe-like trench including alternate wide-width regions and narrow-width regions by etching from a top face of said lower clad layer;
depositing said active layer and said upper clad layer of the second conductive type in this order;
conducting cleavage across each of said narrow-width regions of said stripe-like trench; and
conducting chip segmentation for each of said stripe-like optical cavity.