Nitride semiconductor light-emitting device and method for fabrication thereof
A nitride semiconductor light-emitting device includes a substrate, a nitride semiconductor layer incorporating therein a first electroconductive semiconductor layer, a light-emitting layer and a second electroconductive semiconductor layer, a transparent electrode contiguous to at least part of a first surface of the second electroconductive semiconductor layer, and a second electrode contiguous to the first electroconductive semiconductor layer; wherein the substrate has a first surface thereof provided with a first region exposed by removal of a first part of the nitride semiconductor layer in a peripheral part of the device and a second region exposed by removal of at least a second part of the nitride semiconductor layer contiguous to the transparent electrode except the peripheral part of the device till the substrate. A method for the production of the device includes removing a first part of the nitride semiconductor layer in a peripheral part of the device till the substrate is exposed to form a first exposed region thereof and removing at least a second part of the nitride semiconductor layer contiguous to the transparent electrode except the peripheral part of the device till the substrate is reached to form a second exposed region thereof, wherein the steps are taken by combining the removal with a laser and the removal by wet etching.
1. A method for the production of a nitride semiconductor light-emitting device comprising a substrate, a nitride semiconductor layer incorporating therein a first electroconductive semiconductor layer, a light-emitting layer and a second electroconductive semiconductor layer, a transparent electrode contiguous to at least part of a first surface of the second electroconductive semiconductor layer, and a second electrode contiguous to the first electroconductive semiconductor layer, comprising the steps of:
removing a first part of the nitride semiconductor layer in a peripheral part of the device till the substrate is exposed to form a first exposed region thereof; and
removing at least a second part of the nitride semiconductor layer contiguous to the transparent electrode except the peripheral part of the device till the substrate is reached to form a second exposed region thereof;
wherein the steps are taken by combining the removal first with a laser and then the removal by wet etching.
2. A method for the production of a nitride semiconductor light-emitting device according to claim 1 , wherein the removal of at least the second part of the nitride semiconductor layer is increased in a direction of the substrate by controlling conditions of the wet etching so as to provide the semiconductor layer remaining after the removal with a lateral face tilted toward the substrate.
3. A method for the production of a nitride semiconductor light-emitting device according to claim 1 , wherein the removal of at least the second part of the nitride semiconductor layer is enabled by controlling conditions of the wet etching to have part of the second exposed region of the substrate fall directly below the electrodes.
4. A method for the production of a nitride semiconductor light-emitting device according to claim 1 , wherein the second exposed region of the substrate is provided at a substantially central part thereof with a processed mark in a shape substantially conforming to a shape of the second part of the nitride semiconductor layer by a process using a laser.
5. A method for the production of a nitride semiconductor light-emitting device according to claim 1 , wherein the nitride semiconductor layer having the first part removed has a lateral face tilted outwardly by controlling conditions of the wet etching during the removal of the first part of the nitride semiconductor layer.