# US 2014/0151738 A1 · Roughened high refractive index layer/led for high light extraction > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2014/0151738 A1 - Document ID: US20140151738A1 - Status: Published application - Kind: A1 - Application number: 14/173,662 - Filed: 2014-02-05 - Published: 2014-06-05 - Earliest claimed: 2005-07-21 - Assignees: Cree, Inc. - Applicants: Cree, Inc. - Inventors: STEVEN P. DENBAARS; JAMES IBBETSON; SHUJI NAKAMURA - Web page: https://patentgrep.com/patent/US20140151738A1 ## CPC - H10H 20/82: Roughened surfaces, e.g. at the interface between epitaxial layers - H10H 20/833: Transparent materials - H10H 20/01335: {the light-emitting regions comprising nitride materials} - H10H 20/018: {Bonding of wafers} - H10H: INORGANIC LIGHT-EMITTING SEMICONDUCTOR DEVICES HAVING POTENTIAL BARRIERS ## Abstract A light emitting diode (LED) includes a p-type layer of material, an n-type layer of material and an active layer between the p-type layer and the n-type layer. A roughened layer of transparent material is adjacent one of the p-type layer of material and the n-type layer of material. The roughened layer of transparent material has a refractive index close to or substantially the same as the refractive index of the material adjacent the layer of transparent material, and may be a transparent oxide material or a transparent conducting material. An additional layer of conductive material may be between the roughened layer and the n-type or p-type layer. ## Claims ### Claim 1 A light emitting diode, comprising: a plurality of semiconductor layers comprising a top semiconductor layer, a bottom semiconductor layer, and an active layer between said top and bottom semiconductor layers; a layer of transparent conductive material on said top semiconductor layer, said layer of transparent conductive material comprising a rough primary emission surface; and a contact on said transparent conductive material. ### Claim 2 (depends on 1) The light emitting diode of claim 1, wherein said layer of transparent conductive material is an oxide. ### Claim 3 (depends on 1) The light emitting diode of claim 1, wherein said top semiconductor layer is an n-type layer. ### Claim 4 (depends on 1) The light emitting diode of claim 1, wherein said transparent conductive material has a refractive index within approximately ±0.3 of said plurality of semiconductor layers. ### Claim 5 (depends on 1) The light emitting diode of claim 1, wherein said transparent conductive material comprises at least one of Ga2O3, InO, ZnO, In2O3, ITO, MgO, TiO2, PbO, ZnSnO, NiO, ZnS and CdS. ### Claim 6 A light emitting diode, comprising: a plurality of semiconductor layers; a substantially planar conductive layer on a top one of said semiconductor layers; a transparent layer on said conductive layer, said transparent layer comprising a rough primary emission surface; and a contact on said conductive layer; wherein said conductive layer is one of a transparent conductive oxide and a metal. ### Claim 7 (depends on 6) The light emitting diode of claim 6, wherein said conductive layer is a transparent conductive oxide. ### Claim 8 (depends on 6) The light emitting diode of claim 6, wherein said transparent layer is an oxide. ### Claim 9 (depends on 6) The light emitting diode of claim 6, wherein the bottom of said transparent layer and the bottom of said contact are coplanar. ### Claim 10 (depends on 6) The light emitting diode of claim 6, wherein said transparent layer and said contact are adjacent said conductive layer. ### Claim 11 (depends on 6) The light emitting diode of claim 6, wherein said conductive layer and said transparent layer comprise the same material. ### Claim 12 (depends on 6) The light emitting diode of claim 6, wherein said conductive layer is thinner than said transparent layer. ### Claim 13 (depends on 6) The light emitting diode of claim 6, wherein said contact is on said transparent layer. ### Claim 14 A light emitting diode, comprising: a plurality of semiconductor layers, comprising: an n-type layer; a p-type layer; and an active layer between said n-type and p-type layers; a transparent emission layer on said plurality of semiconductor layers, said emission layer comprising a rough primary emission surface; an n-contact on said plurality of semiconductor layers with one or more layers therebetween. ### Claim 15 (depends on 14) The light emitting diode of claim 14, wherein said emission layer comprises an oxide. ### Claim 16 (depends on 14) The light emitting diode of claim 14, wherein said emission layer is conductive. ### Claim 17 (depends on 16) The light emitting diode of claim 16, wherein said n-contact is on said rough primary emission surface. ### Claim 18 (depends on 14) The light emitting diode of claim 14, wherein said emission layer is adjacent said plurality of semiconductor layers. ### Claim 19 (depends on 14) The light emitting diode of claim 14, further comprising a conductive layer between said plurality of semiconductor layers and said emission layer. ### Claim 20 (depends on 19) The light emitting diode of claim 19, wherein said conductive layer is transparent. ### Claim 21 (depends on 19) The light emitting diode of claim 19, wherein said conductive layer is a transparent conductive oxide. ### Claim 22 (depends on 19) The light emitting diode of claim 19, wherein said conductive layer is metallic. ### Claim 23 (depends on 19) The light emitting diode of claim 19, wherein said n-contact is adjacent said conductive layer. ### Claim 24 (depends on 19) The light emitting diode of claim 19, wherein said n-contact and said emission layer are on a top surface of said conductive layer. ### Claim 25 (depends on 19) The light emitting diode of claim 19, wherein said conductive layer is adjacent said n-type layer. ### Claim 26 A light emitting diode, comprising: a plurality of semiconductor layers; a substantially transparent conducting layer on one of said semiconductor layers; a transparent layer on said transparent conducting layer; and a contact on said transparent conducting layer with said transparent layer at least partially surrounding said contact. ### Claim 27 (depends on 26) The light emitting diode of claim 26, wherein said transparent layer has a higher level of transparency than said transparent conducting layer. ### Claim 28 (depends on 26) The light emitting diode of claim 26, wherein said transparent conducting layer and/or said transparent layer has an index of refraction substantially the same as said semiconductor layers. ### Claim 29 (depends on 26) The light emitting diode of claim 26, wherein said transparent conducting layer and/or said transparent layer comprises a transparent conductive oxide. ### Claim 30 (depends on 26) The light emitting diode of claim 26, wherein said transparent conducting layer comprises Ga2O3, InO, ZnO, In2O3 or ITO. ### Claim 31 (depends on 26) The light emitting diode of claim 26, wherein said transparent layer comprises one or more oxide materials. ### Claim 32 (depends on 26) The light emitting diode of claim 26, wherein said transparent layer comprises Ga2O3, InO, ZnO, In2O3, ITO, MgO, TiO2, PbO, ZnSnO, NiO, ZnS and CdS. ### Claim 33 (depends on 26) The light emitting diode of claim 26, wherein the bottom of said transparent layer and the bottom of said contact are coplanar. ### Claim 34 (depends on 26) The light emitting diode of claim 26, wherein said transparent conducting layer and said transparent layer comprise the same material. ### Claim 35 (depends on 26) The light emitting diode of claim 26, wherein said transparent conducting layer and said transparent layer comprise different materials. ### Claim 36 (depends on 26) The light emitting diode of claim 26, wherein said transparent conducting layer is thinner than said transparent layer. ### Claim 37 (depends on 26) The light emitting diode of claim 26, wherein said transparent conducing layer spreads current from said contact to said semiconductors layers. ### Claim 38 (depends on 26) The light emitting diode of claim 26, wherein said transparent layer comprising a rough emission surface. ### Claim 39 The light emitting diode of said 38, wherein said rough emission surface is on a surface of said transparent layer opposite said transparent conducting layer. ### Claim 40 (depends on 38) The light emitting diode of claim 38, wherein said rough emission surface surrounds said contact.