Light emitting-diode chip and a method for producing same
An LED chip comprising an electrically conductive and radioparent substrate, in which the epitaxial layer sequence ( 3 ) is provided on substantially the full area of its p-side ( 9 ) with a reflective, bondable p-contact layer ( 6 ). The substrate ( 2 ) is provided on its main surface ( 10 ) facing away from the epitaxial layer sequence ( 3 ) with a contact metallization ( 7 ) that covers only a portion of said main surface ( 10 ), and the decoupling of light from the chip ( 1 ) takes place via a bare region of the main surface ( 10 ) of the substrate ( 2 ) and via the chip sides ( 14 ). A further LED chip has epitaxial layers only. The p-type epitaxial layer ( 5 ) is provided on substantially the full area of the main surface ( 9 ) facing away from the n-conductive epitaxial layer ( 4 ) with a reflective, bondable p-contact layer ( 6 ), and the n-conductive epitaxial layer ( 4 ) is provided on its main surface facing away from the p-conductive epitaxial layer ( 5 ) with an n-contact layer ( 7 ) that covers only a portion of said main surface ( 8 ). The decoupling of light from the chip ( 1 ) takes place via the bare region of the main surface ( 8 ) of the n-conductive epitaxial layer ( 4 ) and via the chip sides ( 14 ).
1. A light-emitting diode chip, comprising:
an electrically conductive substrate having a first substrate surface, a second substrate surface opposite the first substrate surface, and at least one side surface;
a GaN-based radiation-emitting epitaxial layer sequence comprising an n-type epitaxial layer deposited on the first substrate surface and a p-type epitaxial layer deposited on the n-type epitaxial layer;
a reflective, bondable p-contact layer comprising a first layer transmissive of radiation emitted by the epitaxial sequence and disposed on a side of the epitaxial layer sequence opposite the substrate and a second layer reflective of radiation emitted by the epitaxial sequence and disposed on the first layer; and
a contact metallization disposed over only a portion of the second substrate surface,
wherein radiation emitted by the epitaxial layer is decoupled through a portion of the second substrate surface over which the metallization is not disposed and through the substrate side surface.
2. The light-emitting diode chip as recited in claim 1 , wherein the electrically conductive substrate is thinned after the deposition of the epitaxial layer sequence.
3. The light-emitting diode chip as recited in claim 2 , wherein the electrically conductive substrate is a silicon carbide substrate.
4. The light-emitting diode chip as recited in claim 2 , wherein the first layer of the reflective, bondable p-contact layer comprises Pt and/or Pd and the second layer of the reflective, bondable p-contact layer comprises Ag, Au and/or Al.
5. The light-emitting diode chip as recited in claim 1 , wherein the electrically conductive substrate is a silicon carbide substrate.
6. The light-emitting diode chip as recited in claim 1 , wherein the first layer of the reflective, bondable p-contact layer comprises Pt and/or Pd and the second layer of the reflective, bondable p-contact layer comprises Ag, Au and/or Al.
7. The light-emitting diode chip as recited in claim 1 , wherein the entire bare surface of, or a subarea of, the layer sequence is roughened.
8. A light-emitting diode chip as claimed in claim 1 , wherein the reflective, bondable p-contact layer is provided on substantially the full area of the p-side of the epitaxial layer sequence.
9. The light-emitting diode chip as recited in claim 1 , wherein the first layer of the reflective, bondable p-contact layer comprises Pt and/or Pd and the second layer of the reflective, bondable p-contact layer is realized as a dielectric mirror.
10. A light-emitting diode chip comprising:
a GaN-based radiation-emitting epitaxial layer sequence comprising a n-type epitaxial layer and a p-type epitaxial layer;
a reflecting, bondable p-contact layer disposed on a surface of the p-type epitaxial layer that is oriented away from the n-type epitaxial layer, the p-contact layer comprising a transparent first layer and, deposited thereon, a reflective second layer;
an n-contact layer disposed over only a portion of a surface of the n-type epitaxial layer that is oriented away from the p-type epitaxial layer;
wherein radiation emitted by the epitaxial layer is decoupled through a portion of the surface of the n-type epitaxial layer over which the n-contact layer is not disposed and through a side of the epitaxial layer sequence and wherein the chip does not include a growth substrate.
11. The light-emitting diode chip as recited in claim 10 , the p-contact layer comprises a PtAg alloy and/or a PdAg alloy.
12. The light-emitting diode chip as recited in claim 10 , wherein the first layer of the reflective, bondable p-contact layer comprises Pt and/or Pd and the second layer of the reflective, bondable p-contact layer comprises Ag, Au and/or Al.
13. A light-emitting diode chip as claimed in claim 10 , wherein the reflective, bondable p-contact layer is provided on substantially the full area of the p-side of the epitaxial layer sequence.
14. The light-emitting diode chip as recited in claim 10 , wherein the first layer of the reflective, bondable p-contact layer comprises Pt and/or Pd and the second layer of the reflective, bondable p-contact layer is realized as a dielectric mirror.