# US 2010/0167501 A1 · Separation of semiconductor devices > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2010/0167501 A1 - Document ID: US20100167501A1 - Status: Published application - Kind: A1 - Application number: 12/667,418 - Filed: 2008-07-03 - Published: 2010-07-01 - Earliest claimed: 2007-07-04 - Assignees: Tinggi Technologies Pte Limited - Inventors: Xuejun Kang; Shu Yuan; Jenny Lam; Shiming Lin - Web page: https://patentgrep.com/patent/US20100167501A1 ## CPC - H10D 62/8503: {Nitride Group III-V materials, e.g. AlN or GaN} - H10H 20/01: Manufacture or treatment - H10H 20/018: {Bonding of wafers} - H10P 72/74: {using temporarily an auxiliary support} - H10H 20/032: {of electrodes} - H10H 20/825: containing nitrogen, e.g. GaN - H10H 20/831: characterised by their shape - H10H 20/832: characterised by their material - H10H 20/84: Coatings, e.g. passivation layers or antireflective coatings - H10H 20/841: Reflective coatings, e.g. dielectric Bragg reflectors - H10P 72/7426: {used as a support during build up manufacturing of active devices} - H10D: INORGANIC ELECTRIC SEMICONDUCTOR DEVICES - H10H: INORGANIC LIGHT-EMITTING SEMICONDUCTOR DEVICES HAVING POTENTIAL BARRIERS - H10P: GENERIC PROCESSES OR APPARATUS FOR THE MANUFACTURE OR TREATMENT OF DEVICES COVERED BY CLASS H10 ## Abstract A method of fabricating semiconductor devices is disclosed. The method comprises providing a substrate with a plurality of epitaxial layers mounted on the substrate and separating the substrate from the plurality of epitaxial layers while the plurality of epitaxial layers is intact. This preserves the electrical, optical, and mechanical properties of the plurality of epitaxial layers. ## Claims ### Claim 1 A method of fabricating semiconductor devices, the method comprising: providing a substrate with a plurality of epitaxial layers mounted on the substrate; and separating the substrate from the plurality of epitaxial layers while the plurality of epitaxial layers are intact while preserving electrical, mechanical and optical properties of the plurality of epitaxial layers. ### Claim 2 (depends on 1) A method as claimed in claim 1, wherein subsequent to separation of the substrate a first stage of device isolation is performed by trench etching. ### Claim 3 (depends on 2) A method as in claim 2, wherein mesas are formed subsequent to separation of the substrate, the trench etching being along edges of each mesa. ### Claim 4 (depends on 3) A method as in claim 3, wherein the mesas are formed in an area defined by the trench. ### Claim 5 (depends on 4) A method as claimed in claim 4, wherein the trench etching is through the epitaxial layer. ### Claim 6 (depends on 2) A method as claimed in claim 2, wherein after the first stage of device isolation the method further comprises pad etching. ### Claim 7 (depends on 6) A method as claimed in claim 6, wherein after pad etching a final stage of die isolation is performed. ### Claim 8 (depends on 3) A method as claimed in claim 3, wherein prior to the first stage of die isolation a photoresist layer is applied to protect regions of an n-type layer of the plurality of epitaxial layers during the etching process. ### Claim 9 (depends on 8) A method as claimed in claim 8, wherein following the first stage of die isolation a first insulating layer is exposed around the mesa, and the photoresist layer is removed. ### Claim 10 (depends on 9) A method as claimed in claim 9, wherein a second insulating layer is applied over the exposed surfaces of the first insulating layer, the sides of the epitaxial layers, and a center of the epitaxial layers; and pad etching takes place to remove at least a part of the second insulating layer to expose part of the surface of the epitaxial layers. ### Claim 11 (depends on 10) A method as claimed in claim 10, wherein a further photoresist layer is applied over exposed surfaces of the second insulating layer and the center of the exposed surface of the epitaxial layers leaving a gap for etching of the exposed surface of the epitaxial layers; etching taking place through the gap to surface texture the exposed surface of the epitaxial layers. ### Claim 12 (depends on 11) A method as claimed in claim 11, wherein the further photoresist layer is removed and a new photoresist layer is applied; etching taking place to expose ends of thick patterns. ### Claim 13 (depends on 8) A method as claimed in claim 8, wherein after die isolation an array of n-type ohmic contacts is formed on the n-type layer. ### Claim 14 (depends on 1) A method as claimed in claim 1, further comprising: prior to separation of the substrate from the plurality of epitaxial layers, forming at least one seed layer on the plurality of epitaxial layers; and forming an outer layer on the at least one seed layer, the outer layer being relatively thick and being for at least one selected from the group consisting of: a new substrate, a structural support, a heat sink, a heat dissipater, a current dissipater, and as a terminal, for the semiconductor devices. ### Claim 15 (depends on 14) A method as claimed in claim 14, wherein before the at least one seed layer is formed: a p-type metal ohmic contact layer is applied to a p-type layer of the plurality of epitaxial layers; a layer of a dielectric is applied over the p-type metal ohmic contact layer and the p-type layer; the dielectric layer is removed from above the metal ohmic contact layer; and the at least one seed layer is deposited on the dielectric layer and the metal ohmic contact layer. ### Claim 16 (depends on 14) A method as claimed in claim 14, wherein the further photoresist layer is removed and a new photoresist layer is applied; etching taking place to expose ends of thick patterns; and after the at least one seed layer is deposited and before the outer layer is formed, the thick patterns are applied to the at least one seed layer, the outer layer being formed between the thick patterns. ### Claim 17 (depends on 15) A method as claimed in claim 15, wherein the dielectric is selected from the group consisting of: an oxide, and a nitride. ### Claim 18 (depends on 13) A method as claimed in claim 13 further comprising die separation as a final step in the process. ### Claim 19 (depends on 1) A method as claimed in claim 1, wherein a laser is used to apply a beam through the substrate to an interface between the substrate and n-the plurality of epitaxial layers to separate the substrate from the plurality of epitaxial layers, the beam being selected from the group consisting of: diverging, and collimated. ### Claim 20 A method of fabricating semiconductor devices, the method comprising: providing a substrate with a plurality of epitaxial layers mounted on the substrate; applying patterns to the plurality of epitaxial layers; forming an outer layer between the patterns; the outer layer being at least 0.3 mm thick and being for at least one selected from the group consisting of: a new substrate, a structural support, a heat sink, a heat dissipater, a current dissipater, and as a terminal, for the semiconductor devices; and separating the substrate from the plurality of epitaxial layers. ### Claim 21 (depends on 20) A method as claimed in claim 20, wherein the outer layer is at least 1 mm thick. ### Claim 22 (depends on 20) A method as claimed in claim 20, wherein the outer layer is at least 2 mm thick. ### Claim 23 (depends on 20) A method as claimed in claim 20, wherein the patterns are of a material that does not adhere to the outer layer such that the outer layer does not require dicing for die separation. ### Claim 24 (depends on 20) A method as claimed in claim 20, wherein the separating the substrate from the plurality of epitaxial layers is while the plurality of epitaxial layers are intact and preserves electrical, mechanical and optical properties of the plurality of epitaxial layers. ### Claim 25 (depends on 20) A method as claimed in claim 20, wherein the patterns define individual devices of the semiconductor devices. ### Claim 26 (depends on 20) A method as claimed in claim 20, wherein prior to applying the patterns, there is included forming at least one seed layer on the plurality of epitaxial layers, the patterns being applied on the at least one seed layer. ### Claim 27 (depends on 26) A method as claimed in claim 26, wherein before the at least one seed layer is formed: a p-type metal ohmic contact layer is applied to a p-type layer of the plurality of epitaxial layers; a layer of a dielectric is applied over the p-type metal ohmic contact layer and the p-type layer; the dielectric layer is removed from above the metal ohmic contact layer; and the at least one seed layer is deposited on the dielectric layer and the metal ohmic contact layer. ### Claim 28 (depends on 20) A method as claimed in claim 20, wherein a laser is used to apply a beam through the substrate to an interface between the substrate and n-the plurality of epitaxial layers to separate the substrate from the plurality of epitaxial layers, the beam being selected from the group consisting of: diverging, and collimated. ### Claim 29 (depends on 5) A method as claimed in claim 5, wherein: after the first stage of device isolation the method further comprises pad etching; after pad etching a final stage of die isolation is performed; prior to the first stage of die isolation a photoresist layer is applied to protect regions of an n-type layer of the plurality of epitaxial layers during the etching process; following the first stage of die isolation a first insulating layer is exposed around the mesa, and the photoresist layer is removed; a second insulating layer is applied over the exposed surfaces of the first insulating layer, the sides of the epitaxial layers, and a center of the epitaxial layers; and pad etching takes place to remove at least a part of the second insulating layer to expose part of the surface of the epitaxial layers; a further photoresist layer is applied over exposed surfaces of the second insulating layer and the center of the exposed surface of the epitaxial layers leaving a gap for etching of the exposed surface of the epitaxial layers; etching taking place through the gap to surface texture the exposed surface of the epitaxial layers; the further photoresist layer is removed and a new photoresist layer is applied; etching taking place to expose ends of thick patterns; after die isolation an array of n-type ohmic contacts is formed on the n-type layer; wherein the method further comprises: prior to separation of the substrate from the plurality of epitaxial layers, forming at least one seed layer on the plurality of epitaxial layers; and forming an outer layer on the at least one seed layer, the outer layer being relatively thick and being for at least one selected from the group consisting of: a new substrate, a structural support, a heat sink, a heat dissipater, a current dissipater, and as a terminal, for the semiconductor devices; before the at least one seed layer is formed: a p-type metal ohmic contact layer is applied to a p-type layer of the plurality of epitaxial layers; a layer of a dielectric is applied over the p-type metal ohmic contact layer and the p-type layer; the dielectric layer is removed from above the metal ohmic contact layer; and the at least one seed layer is deposited on the dielectric layer and the metal ohmic contact layer; and the dielectric is selected from the group consisting of: an oxide, and a nitride. ### Claim 30 (depends on 21) A method as claimed in claim 21, wherein: the outer layer is at least 2 mm thick; the patterns are of a material that does not adhere to the outer layer such that the outer layer does not require dicing for die separation; the separating the substrate from the plurality of epitaxial layers is while the plurality of epitaxial layers are intact and preserves electrical, mechanical and optical properties of the plurality of epitaxial layers; the patterns define individual devices of the semiconductor devices; prior to applying the patterns, there is included forming at least one seed layer on the plurality of epitaxial layers, the patterns being applied on the at least one seed layer; before the at least one seed layer is formed: a p-type metal ohmic contact layer is applied to a p-type layer of the plurality of epitaxial layers; a layer of a dielectric is applied over the p-type metal ohmic contact layer and the p-type layer; the dielectric layer is removed from above the metal ohmic contact layer; and the at least one seed layer is deposited on the dielectric layer and the metal ohmic contact layer; and a laser is used to apply a beam through the substrate to an interface between the substrate and n-the plurality of epitaxial layers to separate the substrate from the plurality of epitaxial layers, the beam being selected from the group consisting of: diverging, and collimated.