# US 2014/0191187 A1 · Submicro-facet light-emitting device and method for fabricating the same > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2014/0191187 A1 - Document ID: US20140191187A1 - Status: Published application - Kind: A1 - Application number: 13/735,771 - Filed: 2013-01-07 - Published: 2014-07-10 - Earliest claimed: 2013-01-07 - Assignees: Invenlux Corporation - Applicants: Invenlux Limited - Inventors: JIANPING ZHANG - Web page: https://patentgrep.com/patent/US20140191187A1 ## CPC - H10H 20/821: of the light-emitting regions, e.g. non-planar junctions - H10H 20/01335: {the light-emitting regions comprising nitride materials} - H10H: INORGANIC LIGHT-EMITTING SEMICONDUCTOR DEVICES HAVING POTENTIAL BARRIERS ## Abstract A light emitting device comprises an n-type layer, a p-type layer, and an active region sandwiched between the n-type layer and the p-type layer, wherein the active-region has a wavy structure with nano or micro fluctuations in its thickness direction. The n-type layer comprises crystal facets on its upper surface, and the active-region is conformally formed on the upper surface of the n-type layer and substantially follows the shape of the crystal facets so as to form the wavy structure. A method for fabricating the same is also provided. ## Claims ### Claim 1 A light emitting device comprising: a substrate; an n-type layer formed over the substrate; a p-type layer; an active region sandwiched between the n-type layer and the p-type layer; wherein the active-region is a continuous layer over substantially an entire upper surface of the substrate and has a wavy structure with nano or micro fluctuations in its thickness direction. ### Claim 2 (depends on 1) The light emitting device according to claim 1, wherein the n-type layer comprises crystal facets on its upper surface, and the active-region is conformally formed on the upper surface of the n-type layer and substantially follows the shape of the crystal facets so as to form the wavy structure. ### Claim 3 (depends on 2) The light-emitting device according to claim 2, wherein the n-type layer comprises (00.1)-oriented III-nitride pillars and the crystal facets are formed on top of the (00.1)-oriented III-nitride pillars, wherein each of the pillars provides six facets due to six-fold crystal structure symmetry; or the n-type layer comprises (111)-oriented III-nitride pillars and the crystal facets are formed on top of the (111)-oriented III-nitride pillars, wherein each of the pillars provides four facets due to four-fold crystal structure symmetry. ### Claim 4 (depends on 3) The light-emitting device according to claim 3, wherein the crystal facets comprise (10.1) facets or (11.1) facets. ### Claim 5 (depends on 3) The light-emitting device according to claim 3, wherein the (00.1)-oriented III-nitride pillars are arranged in a hexagonal lattice pattern with a lattice constant of 150 nm to 1000 nm and the diameter of the pillars is from 140 nm to 1000 nm. ### Claim 6 (depends on 5) The light-emitting device according to claim 5, wherein the (00.1)-oriented III-nitride pillars have a density of 5×108 cm−2 to 5×109 cm−2. ### Claim 7 (depends on 3) The light-emitting device according to claim 3, wherein the (00.1)-oriented III-nitride pillars contain an AlGaN/GaN superlattice structure, with Al-fraction not less than 20%, or contain a GaN/InGaN superlattice structure, with In-fraction not less than 4%. ### Claim 8 (depends on 3) The light-emitting device according to claim 3, wherein the (00.1)-oriented III-nitride pillars contain a strain-modulation structure which contains a silicon concentration peak of above 5×1019 cm−3 with a full-width at half-maximum (FWHM) of 15-20 nm, when being measured by a depth profiling metrology such as secondary ion mass spectrometry (SIMS). ### Claim 9 (depends on 3) The light-emitting device according to claim 3, wherein gaps are formed between neighboring (00.1)-oriented III-nitride pillars, specifically the gaps has a dimension of 3-200 nm. ### Claim 10 (depends on 3) The light-emitting device according to claim 3, wherein the (00.1)-oriented III-nitride pillars have a height larger than 500 nm. ### Claim 11 (depends on 3) The light-emitting device according to claim 3, further comprising a mask layer embedded in the n-type layer, wherein the mask layer consists of a growth suppression area and a growth seeding area formed by nano-scale openings, and the (00.1)-oriented III-nitride pillars grow from and penetrate through the openings. ### Claim at position 12 12-20. (canceled) ### Claim 21 (depends on 5) The light-emitting device according to claim 5, wherein the (00.1)-oriented III-nitride pillars are arranged in a hexagonal lattice pattern with a lattice constant of 150 nm to 500 nm and the diameter of the pillars is from 140 nm to 500 nm. ### Claim 22 A light emitting device comprising: an n-type layer; a p-type layer; an active region sandwiched between the n-type layer and the p-type layer; wherein the active-region has a wavy structure with nano or micro fluctuations in its thickness direction; wherein the n-type layer comprises crystal facets on its upper surface, and the active-region is conformally formed on the upper surface of the n-type layer and substantially follows the shape of the crystal facets so as to form the wavy structure; wherein the n-type layer comprises (00.1)-oriented III-nitride pillars and the crystal facets are formed on top of the (00.1)-oriented III-nitride pillars, wherein each of the pillars provides six facets due to six-fold crystal structure symmetry; or the n-type layer comprises (111)-oriented III-nitride pillars and the crystal facets are formed on top of the (111)-oriented III-nitride pillars, wherein each of the pillars provides four facets due to four-fold crystal structure symmetry; and wherein the (00.1)-oriented III-nitride pillars contain a strain-modulation structure which contains a silicon concentration peak of above 5×1019 cm−3 with a full-width at half-maximum (FWHM) of 15-20 nm, when being measured by a depth profiling metrology such as secondary ion mass spectrometry (SIMS). ### Claim 23 A light emitting device comprising: an n-type layer comprising pillars extruding along a thickness direction of the n-type layer, wherein each of the pillars has a pillar body and a tapering pillar top formed on top of the pillar body, and the tapering pillar top has crystal facets; a p-type layer; an active region sandwiched between the n-type layer and the p-type layer; wherein the active-region has a wavy structure with nano or micro fluctuations in its thickness direction, the active-region is conformally formed on the crystal facets of the tapering pillar tops of the pillars and substantially follows the shape of the crystal facets so as to form the wavy structure. ### Claim 24 (depends on 23) The light-emitting device according to claim 23, wherein the active-region is substantially not formed on side surfaces of the pillar bodies of the pillars. ### Claim 25 (depends on 23) The light-emitting device according to claim 23, wherein the pillars are formed from (00.1)-oriented III-nitride, and each of the pillar tops contains six crystal facets due to six-fold crystal structure symmetry; or the pillars are form from (111)-oriented III-nitride, and each of the pillar tops contains four facets due to four-fold crystal structure symmetry. ### Claim 26 (depends on 23) The light-emitting device according to claim 23, wherein the crystal facets comprise (10.1) facets or (11.1) facets. ### Claim 27 (depends on 25) The light-emitting device according to claim 25, wherein the pillars formed from (00.1)-oriented III-nitride are arranged in a hexagonal lattice pattern with a lattice constant of 150 nm to 1000 nm and the diameter of the pillars is from 140 nm to 1000 nm. ### Claim 28 (depends on 25) The light-emitting device according to claim 25, wherein the pillars formed from (00.1)-oriented III-nitride contain an AlGaN/GaN superlattice structure, with Al-fraction not less than 20%, or contain a GaN/InGaN superlattice structure, with In-fraction not less than 4%. ### Claim 29 (depends on 25) The light-emitting device according to claim 25, wherein the pillars formed from (00.1)-oriented III-nitride contain a strain-modulation structure which contains a silicon concentration peak of above 5×1019 cm−3 with a full-width at half-maximum (FWHM) of 15-20 nm, when being measured by a depth profiling metrology such as secondary ion mass spectrometry (SIMS).