Semiconductor laser element and process for producing the same
AssigneeSharp Kabushiki Kaisha
InventorNobuhiro Ohkubo
Life of this patent
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Abstract
In a semiconductor laser element, a semiconductor layer interface 116 containing oxygen atoms is present above an active layer 103 in at least an internal region of a laser resonator. Also, the peak wavelength of photoluminescence of the active layer 103 in regions in the vicinity of end faces of the laser resonator is made shorter than that of the active layer in the internal region of the laser resonator. In the internal region of the laser resonator, vacancies (crystal defects) produced above and in the neighborhood of the semiconductor layer interface containing oxygen atoms are captured at this semiconductor layer interface. Diffusion of the vacancies to the active layer is thus suppressed.
Claims20
A semiconductor laser element comprising a semiconductor substrate, an active layer formed above the semiconductor substrate, and a plurality of semiconductor layers laid on the active layer, wherein
- at least one of the plurality of semiconductor layers forms a ridge stripe extending in a lengthwise direction of a laser resonator;
- said ridge stripe has a semiconductor layer interface containing oxygen atoms which is located above the active layer at least in an internal region of the laser resonator of the semiconductor laser element;
- and
- a peak wavelength of photo luminescence of the active layer in a region in the vicinity of an end face of the laser resonator is shorter than a peak wavelength of photoluminescence of the active layer in the internal region of the laser resonator.
A semiconductor laser element comprising a semiconductor substrate, an active layer formed above the semiconductor substrate, and a plurality of semiconductor layers laid on the active layer, wherein
- a semiconductor layer interface containing oxygen atoms is located above the active layer at least in an internal region of a laser resonator of the semiconductor laser element;
- a peak wavelength of photoluminescence of the active layer in a region in the vicinity of an end face of the laser resonator is shorter than a peak wavelength of photoluminescence of the active layer in the internal region of the laser resonator;
- and
- the semiconductor layer interface has an oxygen atom concentration that is higher in the internal region of the laser resonator than in the region in the vicinity of the end face of the laser resonator.
A semiconductor laser element comprising a semiconductor substrate, an active layer formed above the semiconductor substrate, and a plurality of semiconductor layers laid on the active layer, wherein
- a semiconductor layer interface containing oxygen atoms is located above the active layer at least in an internal region of a laser resonator of the semiconductor laser element;
- a peak wavelength of photoluminescence of the active layer in a region in the vicinity of an end face of the laser resonator is shorter than a peak wavelength of photoluminescence of the active layer in the internal region of the laser resonator;
- and
- the regrowth interface in the internal region of the laser resonator has an oxygen concentration lower than that of the semiconductor layer interface containing oxygen atoms in the internal region of the laser resonator.
A semiconductor laser element comprising a semiconductor substrate, an active layer formed above the semiconductor substrate, and a plurality of semiconductor layers laid on the active layer, wherein
- a semiconductor layer interface containing oxygen atoms is located above the active layer at least in an internal region of a laser resonator of the semiconductor laser element;
- a peak wavelength of photoluminescence of the active layer in a region in the vicinity of an end face of the laser resonator is shorter than a peak wavelength of photoluminescence of the active layer in the internal region of the laser resonator;
- and
- the semiconductor layer interface containing oxygen atoms is sandwiched between a semiconductor layer containing Al atoms and a semiconductor layer containing no Al atoms, and the semiconductor layer containing Al atoms is located below the semiconductor layer containing no Al atoms.
A process for producing a semiconductor laser element, comprising:
- epitaxially growing semiconductor layers on or above a first-conductive-type semiconductor substrate of a wafer, said semiconductor layers including at least a first-conductive-type cladding layer, an active layer having a multiquantum well structure, a second-conductive-type lower cladding layer, and a second-conductive-type upper cladding layer;
- forming a semiconductor layer interface containing oxygen atoms on the second-conductive-type upper cladding layer in an internal region of a laser resonator of the wafer having the epitaxially grown semiconductor layers;
- and
- making a peak wavelength of photoluminescence of the active layer of the wafer in a region in the vicinity of an end face of the laser resonator shorter than that of the active layer in the internal region of the laser resonator.
A process for producing a semiconductor laser element comprising:
- epitaxially growing semiconductor layers on or above a first-conductive-type semiconductor substrate of a wafer, said semiconductor layers including at least a first-conductive-type cladding layer, an active layer having a multiquantum well structure, a second-conductive-type lower cladding layer, and a second-conductive-type upper cladding layer;
- forming a damaged layer at a surface of the wafer having the semiconductor layers epitaxially grown, in an internal region of the laser resonator;
- forming an oxide film on or above the surface of the wafer in the internal region of the laser resonator as well as in a region in the vicinity of an end face of the laser resonator;
- and
- annealing the wafer to diffuse oxygen atoms below the oxide film and to make a peak wavelength of photoluminescence of the active layer of the wafer in the region in the vicinity of the end face of the laser resonator shorter than that of the active layer in the internal region of the laser resonator.
Dependencies are inferred from the claim text.