Semiconductor laser device and fabrication method thereof

A semiconductor laser device comprising a silicon substrate, and a compound semiconductor layer composed of a nitride semiconductor, having a wurtzite structure, formed on said silicon substrate,

• said silicon substrate including a trench having as a slope a plane inclined 62 degrees from a main plane of said silicon substrate, or a plane inclined within 3 degrees in a direction from the inclined plane,
• said compound semiconductor layer being formed on said slope, and having a lower clad layer, an active layer, and an upper clad layer, each composed of a nitride semiconductor having a wurtzite structure on said compound semiconductor layer, said active layer has a plane orientation substantially equal to the plane orientation of the main plane of said substrate,
• and an upper surface of the compound semiconductor layer is substantially parallel to the plane orientation of said main plane.

A semiconductor laser device comprising a silicon substrate, and a compound semiconductor layer composed of a nitride semiconductor, having a wurtzite structure, formed on said silicon substrate,

• said compound semiconductor layer being formed using a silicon substrate having a main plane composed of a plane corresponding to a (100) plane rotated 7.3 degrees about a axis or a plane inclined in a range within 3 degrees from the rotated plane,
• said silicon substrate including a trench having a (111) plane as a slope, said compound semiconductor layer being formed on said slope, and having a lower clad layer, an active layer, and an upper clad layer, each composed of a nitride semiconductor having a wurtzite structure, on said compound semiconductor layer.
• and an upper surface of the compound semiconductor layer is substantially parallel to the plane orientation of said main plane.

A fabrication method of a semiconductor laser device comprising the steps of:

• forming at a main plane of a substrate, a trench having as a slope a plane inclined 62 degrees from said main plane, or a plane inclined within 3 degrees from the inclined plane,
• growing crystal of a nitride semiconductor, having a wurtzite structure, on said slope to form a compound semiconductor layer having an upper surface substantially parallel to the plane orientation of said main plane,
• sequentially stacking on said compound semiconductor layer a lower clad layer, an active layer, and an upper clad layer, each composed of a nitride semiconductor having a wurtzite structure, such that said active layer has a plane orientation substantially equal to the plane orientation of the main plane of said substrate.

A fabrication method of a semiconductor laser device comprising the steps of:

• forming a trench having a (111) plane as a slope at a main plane of a silicon substrate having said main plane composed of a plane corresponding to a (100) plane rotated 7.3 degrees about a axis, or a plane inclined in a range within 3 degrees from the rotated plane,
• growing crystal of a nitride semiconductor, having a wurtzite structure, on said slope to form a compound semiconductor layer having an upper surface substantially parallel to the plane orientation of said main plane, and
• sequentially stacking on said compound semiconductor layer a lower clad layer, an active layer, and an upper clad layer, each composed of a nitride semiconductor having a wurtzite structure, such that said active layer has a plane orientation substantially equal to the plane orientation of the main plane of said substrate.

A semiconductor laser device comprising a compound semiconductor layer composed of a nitride semiconductor having a wurtzite structure, having a lower clad layer, an active layer, and an upper clad layer formed on said compound semiconductor layer,

• wherein said lower clad layer, said active layer, and said upper clad layer are formed of a nitride semiconductor having a wurtzite structure, and said active layer has a (1-101) plane as a plane orientation, and
• an upper surface of the compound semiconductor layer is substantially parallel to the plane orientation of said main plane, and
• wherein the semiconductor laser device further comprises a laser beam waveguide stripe structure extending along the [11-20]direction of the compound semiconductor layer.