Radiation-emitting semiconductor chip with a radiation-emitting active layer
View Patent ↗Recesses interrupt an active layer on a semiconductor chip to improve the coupling out of light. As a result, side faces of the active layer appear, as seen from a light-generating point, at a large solid angle and the paths of light in the active layer are shortened.
1. A radiation-emitting semiconductor chip, comprising:
a substrate having a main surface area; and
a series or layers disposed on said main surface area, at least one of said layers being a radiation-emitting active layer generating a radiation, said active layer being subdivided into subregions, each of said subregions having side faces disposed transverse to said active layer;
at least one of said active layer and said series of layers being subdivided by recesses, said recesses having side faces, at least one of said recesses having a side face disposed at an angle other than 90° with respect to said main surface area of said substrate;
said at least one of said recesses having at least some of said side faces and a bottom face, said side faces of said at least one of said recesses being separated from one another to cause at least a portion of radiation impinging on said bottom face to be reflected at said bottom face and subsequently be coupled out of at least one of said substrate and said series of layers.
2. The semiconductor chip according to claim 1 , wherein said recesses completely interrupt said active layer.
3. The semiconductor chip according to claim 2 , wherein:
said series of layers has a side facing away from said substrate; and
said recesses extend from said side facing away from said substrate one of up to said main surface area of said substrate and into said substrate.
4. The semiconductor chip according to claim 1 , wherein said active layer is subdivided into tiles.
5. The semiconductor chip according to claim 1 , wherein:
said series of layers has an opposing side opposite said substrate; and
viewed from said opposing side towards said main surface area of said substrate, at least one of said recesses tapers.
6. The semiconductor chip according to claim 1 , wherein:
said active layer has a principal extent; and
a portion of the radiation propagating substantially parallel to a direction of said principal extent impinges on said bottom face.
7. The semiconductor chip according to claim 1 , wherein:
said series of layers has a side facing away from said main surface area; and
viewed from said main surface area, at least one of said recesses tapers in a direction of said side of said series of layers facing away from said main surface area.
8. The semiconductor chip according to claim 1 , wherein said substrate contains a material selected from at least one of a group consisting of silicon, silicon oxide, silicon carbide, and sapphire.
9. The semiconductor chip according to claim 1 , wherein said series of layers contains compounds selected from at least one of a group consisting of GaN, AlGaN, InGaN, AlInGaN.
10. The semiconductor chip according to claim 1 , wherein said active layer contains compounds selected from at least one of a group consisting of GaN, AlGaN, InGaN, AlInGaN.
11. The semiconductor chip according to claim 1 , wherein said series of layers is an epitaxial application to said substrate.
12. A radiation-emitting semiconductor chip, comprising:
a substrate having a main surface area; and
a series of layers disposed on said main surface area, at least one of said layers being a radiation-emitting active layer generating a radiation, said active layer being subdivided into subregions, each of said subregions having side faces disposed transverse to said active layer;
at least one of said active layer and said series of layers being subdivided by recesses;
said series of layers having a side facing away from said main surface area; and
at least one of said recesses tapering in a direction of said side of said series of layers facing away from said main surface area as viewed from said main surface area.
13. The semiconductor chip according to claim 12 , wherein said side faces totally reflect at least part of the radiation generated in said active layer.
14. The semiconductor chip according to claim 13 , wherein:
said active layer has a principal extent; and
said side faces totally reflect a portion of the radiation propagating parallel to said principal extent.
15. The semiconductor chip according to claim 12 , wherein:
said active layer has a principal extent;
said recesses have side faces; and
said side faces transmit a portion of the radiation propagating parallel to said principal extent.
16. The semiconductor chip according to claim 15 , wherein said side faces are separated by a distance to cause said portion of the radiation propagating parallel to said principal extent leaves at least one of said substrate and said series of layers immediately after refraction on one of said side faces.