# US 12,003,076 B2 · Multi-layer metallization for multi-channel emitter array > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,003,076 B2 - Document ID: US12003076B2 - Status: Granted - Kind: B2 - Application number: 16/947,351 - Filed: 2020-07-29 - Published: 2021-11-04 - Granted: 2024-06-04 - Earliest claimed: 2020-04-30 - Assignees: Lumentum Operations LLC - Applicants: Lumentum Operations LLC - Inventors: Ajit Vijay Barve; Matthew Glenn Peters; Eric R. Hegblom - Web page: https://patentgrep.com/patent/US12003076B2 ## CPC - H01S 5/423: {having a vertical cavity} - G01S 7/4815: {using multiple transmitters} - G01S 7/484: Transmitters - G01S 17/10: using transmission of interrupted, pulse-modulated waves (determination of distance by phase measurements G01S17/32) - H01S 5/02345: Wire-bonding - H01S 5/04252: {characterised by the material} - H01S 5/1071: {Ring-lasers} - H01S 5/18305: {with emission through the substrate, i.e. bottom emission} - H01S 5/18311: {using selective oxidation} - H01S 5/1833: {with more than one structure} - H01S 5/04256: {characterised by the configuration} - H01S 5/18308: {having a special structure for lateral current or light confinement} - H01S 5/18347: {Mesa comprising active layer} - H01S 5/2063: {obtained by particle bombardment} - H01S 2301/176: Specific passivation layers on surfaces other than the emission facet - H01S: DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL - G01S: RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES ## Abstract A method for fabricating an array of emitters may include providing a first metallization layer for a first set of emitters of a first channel, wherein the first metallization layer comprises a first interchannel portion positioned between the first set of emitters and a second set of emitters of a second channel. The method may include depositing a dielectric layer on the first interchannel portion of the first metallization layer. The method may include providing a second metallization layer for the second set of emitters, wherein the second metallization layer comprises a second interchannel portion positioned between the first set of emitters and the second set of emitters, and wherein the second interchannel portion of the second metallization layer at least partially overlaps the first interchannel portion of the first metallization layer. ## Claims ### Claim 1 A method, comprising: providing a first metallization layer for a first set of emitters of a first channel, wherein the first metallization layer comprises a first interchannel portion positioned between the first set of emitters and a second set of emitters of a second channel, and wherein the second channel is substantially parallel to the first channel; depositing a dielectric layer on the first interchannel portion of the first metallization layer; and providing a second metallization layer for the second set of emitters, wherein the second metallization layer comprises a second interchannel portion positioned between the first set of emitters and the second set of emitters. ### Claim 2 (depends on 1) The method of claim 1, wherein providing the first metallization layer comprises at least one of forming the first metallization layer with plated metal, forming the first metallization layer using electron-beam physical vapor deposition, or forming the first metallization layer using metal sputtering deposition; or wherein providing the second metallization layer comprises at least one of forming the second metallization layer with plated metal, forming the second metallization layer using electron-beam physical vapor deposition, or forming the second metallization layer using metal sputtering deposition. ### Claim 3 (depends on 1) The method of claim 1, wherein depositing the dielectric layer comprises depositing the dielectric layer using at least one of chemical vapor deposition or atomic layer deposition. ### Claim 4 (depends on 1) The method of claim 1, further comprising: etching, in the dielectric layer, a bondpad for the first metallization layer. ### Claim 5 (depends on 1) The method of claim 1, further comprising: before providing the first metallization layer, depositing active layers on a substrate layer to form the first set of emitters and the second set of emitters. ### Claim 6 (depends on 5) The method of claim 5, further comprising, before providing the first metallization layer and after depositing the active layers: positioning a first set of contacts on an uppermost layer of the active layers for each emitter of the first set of emitters of the first channel; positioning a second set of contacts on the uppermost layer of the active layers for each emitter of the second set of emitters of the second channel; and etching trenches in the active layers for each emitter of the first set of emitters and for each emitter of the second set of emitters. ### Claim 7 (depends on 6) The method of claim 6, further comprising, after etching trenches in the active layers, oxidizing the first set of emitters and the second set of emitters. ### Claim 8 (depends on 6) The method of claim 6, wherein the dielectric layer is a second dielectric layer; and wherein the method further comprises, after etching trenches in the active layers: depositing a first dielectric layer on the active layers; and etching, in the first dielectric layer, vias for the first set of contacts. ### Claim 9 (depends on 8) The method of claim 8, wherein: providing the first metallization layer comprises providing, after etching vias for the first set of contacts, the first metallization layer on the first set of contacts and the first dielectric layer; and depositing the second dielectric layer comprises depositing, after providing the first metallization, the second dielectric layer on the first metallization layer and the first dielectric layer. ### Claim 10 (depends on 9) The method of claim 9, further comprising: after depositing the second dielectric layer, etching, in the second dielectric layer and the first dielectric layer, vias for the second set of contacts; and wherein providing the second metallization layer comprises providing, after etching vias for the second set of contacts, the second metallization layer on the second set of contacts and the second dielectric layer. ### Claim 11 (depends on 10) The method of claim 10, further comprising: positioning a third set of contacts on the active layers for each emitter of a third set of emitters of a third channel, wherein the second metallization layer comprises a third interchannel portion positioned between the second set of emitters and the third set of emitters; depositing a third dielectric layer on the second metallization layer and the second dielectric layer; and providing a third metallization layer on the third set of contacts and the third dielectric layer, wherein the third metallization layer comprises a fourth interchannel portion positioned between the second set of emitters and the third set of emitters. ### Claim 12 (depends on 1) The method of claim 1, wherein the first metallization layer at least partially overlaps emission areas of the first set of emitters, and wherein the second metallization layer at least partially overlaps emission areas of the second set of emitters. ### Claim 13 An optical chip, comprising: a first channel comprising a first set of emitters; a first set of contacts for the first set of emitters; a first dielectric layer; a first metallization layer on the first set of contacts and the first dielectric layer, wherein the first metallization layer comprises a first interchannel portion positioned between the first set of emitters and a second set of emitters; a second channel comprising the second set of emitters, wherein the second channel is substantially parallel to the first channel; a second set of contacts for the second set of emitters; a second dielectric layer on the first metallization layer and the first dielectric layer; and a second metallization layer on the second set of contacts and the second dielectric layer, wherein the second metallization layer comprises a second interchannel portion positioned between the first set of emitters and the second set of emitters, and wherein the second interchannel portion of the second metallization layer at least partially overlaps the first interchannel portion of the first metallization layer. ### Claim 14 (depends on 13) The optical chip of claim 13, wherein the first metallization layer comprises at least one of gold, aluminum, copper, or nickel gold; or wherein the second metallization layer comprises at least one of gold, aluminum, copper, or nickel gold. ### Claim 15 (depends on 13) The optical chip of claim 13, wherein the first set of contacts comprises at least one of p-ohmic metal, n-ohmic metal, titanium, gold, or platinum; or wherein the second set of contacts comprises at least one of p-ohmic metal, n-ohmic metal, titanium, gold, or platinum. ### Claim 16 (depends on 13) The optical chip of claim 13, wherein the first dielectric layer comprises at least one of a silicon nitride (Si3N4) layer, a silicon dioxide (SiO2) layer, or an aluminum oxide (Al2O3) layer; or wherein the second dielectric layer comprises at least one of a silicon nitride (Si3N4) layer, a silicon dioxide (SiO2) layer, or an aluminum oxide (Al2O3) layer. ### Claim 17 (depends on 13) The optical chip of claim 13, wherein the first set of emitters and the second set of emitters are top-emitting vertical-cavity surface-emitting lasers. ### Claim 18 (depends on 13) The optical chip of claim 13, wherein the first set of emitters and the second set of emitters are bottom-emitting vertical-cavity surface-emitting lasers; wherein the first metallization layer at least partially overlaps emission areas of the first set of emitters; and wherein the second metallization layer at least partially overlaps emission areas of the second set of emitters. ### Claim 19 (depends on 13) The optical chip of claim 13, further comprising: a third channel comprising a third set of emitters; a third set of contacts for the third set of emitters; and a third metallization layer on the third set of contacts and the first dielectric layer, wherein the third metallization layer comprises a third interchannel portion positioned between the second set of emitters and the third set of emitters, wherein the second dielectric layer is on the third metallization layer, wherein the second metallization layer comprises a fourth interchannel portion positioned between the second set of emitters and the third set of emitters, and wherein the fourth interchannel portion of the second metallization layer at least partially overlaps the third interchannel portion of the third metallization layer. ### Claim 20 A time-of-flight system, comprising: an array of emitters to emit optical beams into a field of view, wherein the array of emitters comprises: a first channel comprising a first set of emitters, a second channel comprising a second set of emitters, wherein the second channel is substantially parallel to the first channel, a first metallization layer to provide electrical contact between a drive circuit and the first set of emitters, a dielectric layer on the first metallization layer, and a second metallization layer, on the dielectric layer, to provide electrical contact between the drive circuit and the second set of emitters, wherein the second metallization layer at least partially overlaps with the first metallization layer; the drive circuit; and a receiver to receive light reflected from the field of view. ### Claim 21 (depends on 20) The time-of-flight system of claim 20, wherein the first set of emitters and the second set of emitters comprise at least one of top-emitting vertical-cavity surface-emitting lasers (VCSELs), bottom-emitting VCSELs, common anode VCSELs, common cathode VCSELs, or line scanning lasers. ### Claim 22 (depends on 20) The time-of-flight system of claim 20, wherein the dielectric layer is positioned between overlapping portions of the first metallization layer and the second metallization layer. ### Claim 23 (depends on 20) The time-of-flight system of claim 20, wherein the first metallization layer comprises a first bondpad, wherein the second metallization layer comprises a second bondpad, and wherein the drive circuit is electrically connected to the first bondpad and the second bondpad. ### Claim 24 (depends on 20) The time-of-flight system of claim 20, wherein: the drive circuit is configured to generate one or more drive signals to drive the array of emitters to emit the optical beams into the field of view; the receiver is configured to generate, based on the light reflected from the field of view, electrical signals; and the time-of-flight system is configured to determine, based on the drive signals and the electrical signals, distances to one or more objects in the field of view.