# US 12,009,454 B2 · Light emitting device > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,009,454 B2 - Document ID: US12009454B2 - Status: Granted - Kind: B2 - Application number: 17/507,058 - Filed: 2021-10-21 - Published: 2022-05-19 - Granted: 2024-06-11 - Earliest claimed: 2020-11-16 - Assignees: Nichia Corporation - Applicants: Nichia Corporation - Inventors: Takuya Okada - Web page: https://patentgrep.com/patent/US12009454B2 ## CPC - H10H 20/812: within the light-emitting regions, e.g. having quantum confinement structures - H10H 20/825: containing nitrogen, e.g. GaN - H10H 20/811: having quantum effect structures or superlattices, e.g. tunnel junctions - H10H 20/8252: {characterised by the dopants} - H10H 20/815: having stress relaxation structures, e.g. buffer layers - H10H 20/8215: {characterised by crystalline imperfections, e.g. dislocations; characterised by the distribution of dopants, e.g. delta-doping} - H10H: INORGANIC LIGHT-EMITTING SEMICONDUCTOR DEVICES HAVING POTENTIAL BARRIERS ## Abstract A light-emitting device includes an n-side semiconductor layer comprising an n-type contact layer and an intermediate layer located on the n-type contact layer; an active layer located on the intermediate layer; and a p-side semiconductor layer located on the active layer. The intermediate layer includes at least one stacked portion comprising a first layer and a second layer. The first layer is an n-type nitride semiconductor layer comprising an n-type impurity, Al, and Ga. The second layer is a nitride semiconductor layer that includes Al and Ga, has a lower n-type impurity concentration than the first layer, and has a larger thickness than the first layer. An Al composition ratio of the first layer is higher than an Al composition ratio of the second layer. ## Claims ### Claim 1 A light-emitting device comprising: an n-side semiconductor layer comprising an n-type contact layer, and an intermediate layer located on the n-type contact layer; an active layer located on the intermediate layer; a p-side semiconductor layer located on the active layer; and an n-side electrode contacting the n-type contact layer, wherein: the intermediate layer comprises at least one stacked portion comprising a first layer and a second layer, the first layer is an n-type nitride semiconductor layer comprising an n-type impurity, Al, and Ga, the second layer is a nitride semiconductor layer that comprises Al and Ga, and has a larger thickness than the first layer, an n-type impurity concentration of the first layer is lower than an n-type impurity concentration of the n-type contact layer, an n-type impurity concentration of the second layer is lower than the n-type impurity concentration of the first layer, and an Al composition ratio of the first layer is higher than an Al composition ratio of the second layer. ### Claim 2 (depends on 1) The device according to claim 1, wherein the at least one stacked portion comprises a plurality of the stacked portions. ### Claim 3 (depends on 2) The device according to claim 2, wherein an Al composition ratio of a first layer located closest to the active layer, among a plurality of first layers of the plurality of stacked portions, is higher than an Al composition ratio of other first layers of the plurality of first layers. ### Claim 4 (depends on 3) The device according to claim 3, wherein an n-type impurity concentration of a first layer located closest to the active layer, among a plurality of first layers of the plurality of stacked portions, is higher than an n-type impurity concentration of other first layers of the plurality of first layers. ### Claim 5 (depends on 4) The device according to claim 4, wherein the intermediate layer further comprises a nitride semiconductor layer that is located between the first layer located closest to the active layer and the active layer, has a lower n-type impurity concentration than the first layer located closest to the active layer, and comprises Al and Ga. ### Claim 6 (depends on 3) The device according to claim 3, wherein an n-type impurity concentration of a second layer located closest to the active layer, among a plurality of second layers of the plurality of stacked portions, is higher than an n-type impurity concentration of other second layers of the plurality of stacked portions. ### Claim 7 (depends on 3) The device according to claim 3, wherein the thickness of the second layer is 10 times or more the thickness of the first layer. ### Claim 8 (depends on 3) The device according to claim 3, wherein the thickness of the second layer is 50 nm or more and 100 nm or less. ### Claim 9 (depends on 3) The device according to claim 3, wherein the first layer is made of Ala1Ga1−a1N (0