SEMICONDUCTOR DEVICE AND MANUFACTURING METHOD OF SEMICONDUCTOR DEVICE
First Claim
1. A semiconductor device comprising:
- a substrate;
a first nitride semiconductor layer arranged over a major plane of the substrate;
a second nitride semiconductor layer arranged over the first nitride semiconductor layer;
a third nitride semiconductor layer arranged over the second nitride semiconductor layer;
a fourth nitride semiconductor layer arranged between the first nitride semiconductor layer and the second nitride semiconductor layer; and
a side face at which the second nitride semiconductor layer is exposed,wherein the side face extends in a first direction,wherein the fourth nitride semiconductor layer is arranged being retracted from the side face, in second areas on both sides of a first area extending in a second direction that intersects the first direction,wherein a band gap of the first nitride semiconductor layer, which is a first conductive type, is larger than that of the second nitride semiconductor layer,wherein a band gap of the third nitride semiconductor layer, which is a second conductive type that is a opposite conductive type of the first conductive type, is larger than that of the second nitride semiconductor layer;
wherein a band gap of the fourth nitride semiconductor layer, which contains Al, is larger than that of the third nitride semiconductor layer;
wherein the major plane of the substrate has an off-angle in a <
1-100>
direction from a (0001) plane, andwherein a layer thickness of a third area from the side face of the second nitride semiconductor layer up to an end part of the fourth nitride semiconductor layer is smaller than a layer thickness of the first area.
2 Assignments
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Accused Products
Abstract
To provide a semiconductor laser that suppresses end face destruction due to catastrophic optical damage (COD) to a light emission end face and has high output characteristics.
An n-type clad layer, a current block layer, an active layer, and a p-type clad layer are provided over an n-type substrate whose major plane has an off-angle in a <1-100>direction from a (0001) plane. For example, the current block layer is arranged on both sides of a current constriction area. Then, the current block layer is arranged so as to be retracted from a cleavage plane (line). In this case, in the active layer having a quantum well structure that is crystal-grown over the n-type clad layer and the current block layer, the layer thickness of a window area from the cleavage plane (line) up to the end part of the current block layer is smaller than the layer thickness of the current constriction area (area between the current block layers). As a result, the band gap of the active layer in the window area becomes large, and thus it is possible to suppress end face destruction due to the COD.
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Citations
20 Claims
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1. A semiconductor device comprising:
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a substrate; a first nitride semiconductor layer arranged over a major plane of the substrate; a second nitride semiconductor layer arranged over the first nitride semiconductor layer; a third nitride semiconductor layer arranged over the second nitride semiconductor layer; a fourth nitride semiconductor layer arranged between the first nitride semiconductor layer and the second nitride semiconductor layer; and a side face at which the second nitride semiconductor layer is exposed, wherein the side face extends in a first direction, wherein the fourth nitride semiconductor layer is arranged being retracted from the side face, in second areas on both sides of a first area extending in a second direction that intersects the first direction, wherein a band gap of the first nitride semiconductor layer, which is a first conductive type, is larger than that of the second nitride semiconductor layer, wherein a band gap of the third nitride semiconductor layer, which is a second conductive type that is a opposite conductive type of the first conductive type, is larger than that of the second nitride semiconductor layer; wherein a band gap of the fourth nitride semiconductor layer, which contains Al, is larger than that of the third nitride semiconductor layer; wherein the major plane of the substrate has an off-angle in a <
1-100>
direction from a (0001) plane, andwherein a layer thickness of a third area from the side face of the second nitride semiconductor layer up to an end part of the fourth nitride semiconductor layer is smaller than a layer thickness of the first area. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13)
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14. A manufacturing method of a semiconductor device comprising the steps of:
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(a) forming a first nitride semiconductor layer over a substrate whose major plane has an off-angle in a <
1-100>
direction from a (0001) plane;(b) forming a second nitride semiconductor layer over the first nitride semiconductor layer; (c) causing the second nitride semiconductor layer to remain, so as to be arranged being retracted from a side face line, in second areas on both sides of a first area extending in a second direction that intersects the side face line extending in a first direction of the first nitride semiconductor layer by etching the second nitride semiconductor layer; and (d) forming a third nitride semiconductor layer over the first nitride semiconductor layer and the second nitride semiconductor layer. - View Dependent Claims (15, 16, 17, 18, 19, 20)
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Specification