# US 12,604,571 B2 · Light emitting diodes with lattice matching sidewall passivation layer and method of making thereof > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,604,571 B2 - Document ID: US12604571B2 - Status: Granted - Kind: B2 - Application number: 17/937,878 - Filed: 2022-10-04 - Published: 2023-04-13 - Granted: 2026-04-14 - Earliest claimed: 2021-10-07 - Assignees: Samsung Electronics Co., Ltd. - Applicants: Samsung Electronics Co., Ltd. - Inventors: Saket Chadda - Web page: https://patentgrep.com/patent/US12604571B2 ## CPC - H10H 20/84: Coatings, e.g. passivation layers or antireflective coatings - H10H 20/0133: {with a substrate not being Group III-V materials} - H10H 20/01335: {the light-emitting regions comprising nitride materials} - H10H 20/821: of the light-emitting regions, e.g. non-planar junctions - H10H 20/824: comprising only Group III-V materials, e.g. GaP - H10H 20/825: containing nitrogen, e.g. GaN - H10H 20/833: Transparent materials - H10H 20/841: Reflective coatings, e.g. dielectric Bragg reflectors - H10H 20/857: Interconnections, e.g. lead-frames, bond wires or solder balls - H10H 20/032: {of electrodes} - H10H 20/034: {of coatings} - H10H 20/0364: {of interconnections} - H10H 20/817: characterised by the crystal structures or orientations, e.g. polycrystalline, amorphous or porous - H10H: INORGANIC LIGHT-EMITTING SEMICONDUCTOR DEVICES HAVING POTENTIAL BARRIERS ## Abstract A light emitting diode includes a mesa structure containing a first-conductivity-type compound semiconductor layer, an active layer stack configured to emit light at a peak wavelength, and a second-conductivity-type compound semiconductor layer, and a passivation material layer contacting at least a sidewall of the mesa structure. The passivation material layer has a first crystal structure that matches a second crystal structure of the first-conductivity-type compound semiconductor layer and the second-conductivity-type compound semiconductor layer. ## Claims ### Claim 1 A light emitting diode, comprising: a mesa structure comprising a first-conductivity-type compound semiconductor layer, an active layer stack configured to emit light at a peak wavelength, and a second-conductivity-type compound semiconductor layer; and a passivation material layer contacting at least a sidewall of the mesa structure, wherein the passivation material layer comprises a first crystal structure that matches a second crystal structure of the first-conductivity-type compound semiconductor layer and the second-conductivity-type compound semiconductor layer, wherein the first-conductivity-type compound semiconductor layer and the second-conductivity-type compound semiconductor layer comprise phosphorous, and wherein the passivation material layer comprises ZnS, GaAs or GaP. ### Claim 2 (depends on 1) The light emitting diode of claim 1, wherein the first-conductivity-type compound semiconductor layer and the second-conductivity-type compound semiconductor layer each comprise doped Group III-phosphide material. ### Claim 3 (depends on 1) The light emitting diode of claim 1, further comprising: a doped compound semiconductor layer located between a substrate and the first-conductivity-type compound semiconductor layer; and a transparent conductive layer located over the second-conductivity-type compound semiconductor layer. ### Claim 4 (depends on 3) The light emitting diode of claim 3, wherein the passivation material layer laterally surrounds the mesa structure and comprises: an upper horizontal portion that overlies a peripheral region of a top side of the mesa structure; a bottom horizontal portion which contacts a top surface of the doped compound semiconductor layer; and a sidewall portion which contacts the sidewall of the mesa structure and is adjoined to a periphery of the upper and lower horizontal portions. ### Claim 5 (depends on 4) The light emitting diode of claim 4, wherein: the upper horizontal portion is located above the transparent conductive layer; and an opening in the upper horizontal portion is located over a center region of the mesa structure and exposes the transparent conductive layer. ### Claim 6 (depends on 5) The light emitting diode of claim 5, further comprising a reflector layer laterally surrounding and contacting an outer surface of the sidewall portion of the passivation material layer, wherein the reflector layer electrically contacts the transparent conductive layer through the opening. ### Claim 7 (depends on 6) The light emitting diode of claim 6, further comprising: a first conductive bonding structure overlying and electrically connected to the transparent conductive layer a dielectric matrix layer laterally surrounding the passivation material layer; a contact via structure vertically extending through the dielectric matrix layer and electrically contacting the doped compound semiconductor layer; a second conductive bonding structure overlying and electrically connected to the contact via structure; and a backplane electrically connected to the first conductive bonding structure and the second conductive bonding structure. ### Claim 8 (depends on 1) The light emitting diode according to claim 1, wherein the first crystal structure and the second crystal structure are a zinc blende crystal structure. ### Claim 9 A method of forming a light emitting diode, comprising: forming a first-conductivity-type compound semiconductor layer, an active layer stack configured to emit light at a peak wavelength, and a second-conductivity-type compound semiconductor layer over a substrate; forming a mesa structure by etching the first-conductivity-type compound semiconductor layer, the active layer stack and the second-conductivity-type compound semiconductor layer; and forming a passivation material layer in contact with at least a sidewall of the mesa structure, wherein the passivation material layer comprises a first crystal structure that matches a second crystal structure of the first-conductivity-type compound semiconductor layer and the second-conductivity-type compound semiconductor layer, wherein the first-conductivity-type compound semiconductor layer and the second-conductivity-type compound semiconductor layer comprise phosphorous, and wherein the passivation material layer comprises ZnS, GaAs or GaP. ### Claim 10 (depends on 9) The method of claim 9, wherein the first-conductivity-type compound semiconductor layer and the second-conductivity-type compound semiconductor layer each comprise doped Group III-phosphide material. ### Claim 11 (depends on 9) The method of claim 9, further comprising: forming a transparent conductive oxide layer over the second-conductivity-type compound semiconductor layer prior to forming the passivation material layer; forming an opening through the upper portion of the passivation material layer over a center region of the mesa structure to expose the transparent conductive oxide layer; forming a continuous reflector layer over the passivation material layer and in the opening such that the continuous reflector layer is electrically connected to the transparent conductive oxide layer; and patterning the continuous reflector layer to form a reflector layer that laterally surrounds the mesa structure and the passivation material layer. ### Claim 12 (depends on 11) The method of claim 11, wherein the passivation material layer laterally surrounds the mesa structure and comprises: an upper horizontal portion that overlies a peripheral region of a top side of the mesa structure; a bottom horizontal portion which contacts a top surface of the doped compound semiconductor layer; and a sidewall portion which contacts the sidewall of the mesa structure and is adjoined to a periphery of the upper and lower horizontal portions. ### Claim 13 (depends on 11) The method of claim 11, further comprising forming a first conductive bonding structure on a physically exposed surface of the reflector layer. ### Claim 14 (depends on 13) The method of claim 13, further comprising: forming a dielectric matrix layer laterally surrounding the passivation material layer; forming a contact via structure vertically extending through the dielectric matrix layer and contacting a doped compound semiconductor layer located between the substrate and the first-conductivity-type compound semiconductor layer; forming a second conductive bonding structure overlying and electrically connected to the contact via structure; and electrically contacting the first conductive bonding structure and the second conductive bonding structure to a backplane. ### Claim 15 (depends on 9) The method according to claim 9, wherein the first crystal structure and the second crystal structure are a zinc blende crystal structure. ### Claim 16 A light emitting diode, comprising: a mesa structure comprising a first-conductivity-type compound semiconductor layer, an active layer stack configured to emit light at a peak wavelength, and a second-conductivity-type compound semiconductor layer; and a passivation material layer contacting at least a sidewall of the mesa structure, wherein the passivation material layer comprises a first crystal structure that matches a second crystal structure of the first-conductivity-type compound semiconductor layer and the second-conductivity-type compound semiconductor layer, wherein the passivation material layer comprises ZnS, GaAs or GaP.