# US 8,541,251 B2 · Method for manufacturing 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 8,541,251 B2 - Document ID: US8541251B2 - Status: Granted - Kind: B2 - Application number: 13/548,632 - Filed: 2012-07-13 - Published: 2013-01-24 - Granted: 2013-09-24 - Earliest claimed: 2011-07-21 - Assignees: Hamamatsu Photonics K.K. - Applicants: Naoki Uchiyama - Inventors: Naoki Uchiyama - Web page: https://patentgrep.com/patent/US8541251B2 ## CPC - B23K 26/0617: {and with spots spaced along the common axis} - B23K 26/40: taking account of the properties of the material involved - B23K 26/53: for modifying or reforming the material inside the workpiece, e.g. for producing break initiation cracks - H10H 20/01: Manufacture or treatment - B23K 2101/40: Semiconductor devices - B23K 2103/172: {wherein at least one of the layers is non-metallic} - B23K 2103/50: {Inorganic materials other than metals or composite materials} - H01S 5/0201: {Separation of the wafer into individual elements, e.g. by dicing, cleaving, etching or directly during growth} - H01S 5/0202: {Cleaving} - H01S 5/32341: {blue laser based on GaN or GaP} - B23K: SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM - H10H: INORGANIC LIGHT-EMITTING SEMICONDUCTOR DEVICES HAVING POTENTIAL BARRIERS - 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 ## Abstract A light-emitting device manufacturing method comprises the steps of irradiating a substrate 2 having a III-V compound semiconductor layer 17 formed on a front face 2a with laser light L1 along lines to cut 5a, 5b, while locating a converging point P1 within the sapphire substrate 2 and using a rear face 2b thereof as a laser light entrance surface, and thereby forming modified regions 7a, 7b along the lines 5a, 5b within the substrate 2; then forming a light-reflecting layer on the rear face 2b of the substrate 2; and thereafter extending fractures generated from the modified regions 7a, 7b acting as a start point in the thickness direction of the substrate 2, and thereby cutting the substrate 2, the semiconductor layer 17 and the light-reflecting layer along the lines 5a, 5b, and manufacturing a light-emitting device. ## Claims ### Claim 1 A method for manufacturing a light-emitting device comprising: a second step of irradiating a sapphire substrate having a front face formed with a III-V compound semiconductor layer with first laser light along a predetermined line to cut while locating a converging point within the sapphire substrate and using a rear face of the sapphire substrate as a laser entrance surface, and thereby forming a modified region within the sapphire substrate along the line; a third step of forming a light-reflecting layer on the rear face of the sapphire substrate after the second step; and a fourth step of extending a fracture generated from the modified region acting as a start point in a thickness direction of the sapphire substrate after the third step, and thereby cutting the sapphire substrate, the III-V compound semiconductor layer and the light-reflecting layer along the line, and manufacturing the light-emitting device. ### Claim 2 (depends on 1) A method for manufacturing a light-emitting device according to claim 1, wherein, in the second step, the modified region is formed within the sapphire substrate along the line so that the fracture to be extended in the thickness direction of the sapphire substrate in the fourth step reaches at least the front face of the sapphire substrate beforehand. ### Claim 3 (depends on 1) A method for manufacturing a light-emitting device according to claim 1, wherein, in the second step, the modified region is formed within the sapphire substrate along the line so that the fracture to be extended in the thickness direction of the sapphire substrate in the fourth step reaches the rear face of the sapphire substrate beforehand. ### Claim 4 (depends on 1) A method for manufacturing a light-emitting device according to claim 1, wherein, in the fourth step, a knife edge is pressed along the line from the light-reflecting layer side, and thereby the fracture generated from the modified region acting as the start point is extended in the thickness direction. ### Claim 5 (depends on 1) A method for manufacturing a light-emitting device according to claim 1, further comprising the step of irradiating the sapphire substrate with second laser light absorbable in the light-reflecting layer from the light-reflecting layer side along the line after the third step but before the fourth step, and thereby extending the fracture generated from the modified region acting as the start point in the thickness direction of the sapphire substrate; wherein, in the fourth step, the fracture generated from the modified region acting as the start point is further extended in the thickness direction of the sapphire substrate, and thereby the sapphire substrate, the III-V compound semiconductor layer and the light-reflecting layer are cut along the line. ### Claim 6 (depends on 1) A method for manufacturing a light-emitting device according to claim 1, wherein in the fourth step, the sapphire substrate is irradiated with second laser light absorbable in the light-reflecting layer from the light-reflecting layer side along the line, and thereby the fracture generated from the modified region acting as the start point is extended in the thickness direction of the sapphire substrate. ### Claim 7 (depends on 1) A method for manufacturing a light-emitting device according to claim 1, further comprising the step of irradiating the sapphire substrate with third laser light transmittable through the III-V compound semiconductor layer from the III-V compound semiconductor layer side along the line while locating a converging point within the sapphire substrate after the third step but before the fourth step, and thereby extending the fracture generated from the modified region acting as the start point in the thickness direction of the sapphire substrate; wherein, in the fourth step, the fracture generated from the modified region acting as the start point is further extended in the thickness direction of the sapphire substrate, and thereby the sapphire substrate, the III-V compound semiconductor layer and the light-reflecting layer are cut along the line. ### Claim 8 (depends on 1) A method for manufacturing a light-emitting device according to claim 1, wherein, in the fourth step, the sapphire substrate is irradiated with third laser light transmittable through the III-V compound semiconductor layer from the III-V compound semiconductor layer side along the line while locating a converging point within the sapphire substrate, and thereby the fracture generated from the modified region acting as the start point is extended in the thickness direction of the sapphire substrate. ### Claim 9 (depends on 7) A method for manufacturing a light-emitting device according to claim 7, wherein the sapphire substrate is irradiated with the third laser light from the III-V compound semiconductor layer side along the line in only an intersecting part of the line. ### Claim 10 (depends on 1) A method for manufacturing a light-emitting device according to claim 1, further comprising a first step of forming the III-V compound semiconductor layer on the front face of the sapphire substrate before the second step. ### Claim 11 (depends on 8) A method for manufacturing a light-emitting device according to claim 8, wherein the sapphire substrate is irradiated with the third laser light from the III-V compound semiconductor layer side along the line in only an intersecting part of the line.