Method of fabricating light emitting diode chip
View Patent ↗The present invention provides a method of fabricating a light emitting diode chip having an active layer between an N type semiconductor layer and a P type semiconductor layer. The method comprises the steps of preparing a substrate; laminating the semiconductor layers on the substrate, the semiconductor layers having the active layer between the N type semiconductor layer and the P type semiconductor layer; and forming grooves on the semiconductor layers laminated on the substrate until the substrate is exposed, whereby inclined sidewalls are formed by the grooves in the semiconductor layers divided into a plurality of chips. According to embodiments of the present invention, a sidewall of a semiconductor layer formed on a substrate of a light emitting diode chip is inclined with respect to the substrate, whereby its directional angle is widened as compared with a light emitting diode chip without such inclination. As the directional angle of the light emitting diode chip is wider, when a white light emitting device is fabricated using the light emitting diode chip and a phosphor, light uniformity can be adjusted even though the phosphor is not concentrated at the center of the device. Thus, the overall light emitting efficiency can be enhanced by reducing a light blocking phenomenon caused by the increased amount of the phosphor distributed at the center portion.
1. A method of fabricating a light-emitting diode chip, the method comprising:
forming a first-type semiconductor layer, an active layer, and a second-type semiconductor layer on a first surface of a substrate, the active layer being disposed between the first-type semiconductor layer and the second-type semiconductor layer;
forming a plurality of photoresist patterns on the second-type semiconductor layer, the photoresist patterns to define a plurality of light emitting regions;
etching the first-type semiconductor layer, the active layer, and the second-type semiconductor layer using the photoresist patterns as an etching mask, thereby exposing a first portion of the first-type semiconductor layer;
forming a plurality of metallic wires on the second-type semiconductor layer and the exposed first portion of the first-type semiconductor layer; and
forming a plurality of grooves in the first-type semiconductor layer, the active layer, and the second-type semiconductor layer, the grooves exposing the substrate,
wherein the grooves include inclined sidewalls that extend at a non-perpendicular angle with respect to the first surface of the substrate, through the first-type semiconductor layer, the active layer, and the second-type semiconductor layer.
2. The method of claim 1 , wherein forming the plurality of grooves divides the first-type semiconductor layer, the active layer, and the second-type semiconductor layer into a plurality of light-emitting diode chips.
3. The method of claim 1 , wherein forming the grooves comprises cutting the first-type semiconductor layer, the active layer, and the second-type semiconductor layer using a blade comprising an inclined edge.
4. The method of claim 3 , wherein the blade edge is inclined at an angle between 50° and 150°.
5. The method of claim 3 , wherein the inclined sidewalls are inclined at an angle between 25° and 75° with respect to the first surface of the substrate.
6. The method of claim 1 , further comprising:
performing a scribing process on the substrate after forming the inclined sidewalls; and
breaking the scribed substrate to separate the light-emitting diode chips.
7. The method of claim 6 , wherein the scribing process is performed on a bottom surface or a top surface of the substrate using a diamond tip or a laser.
8. The method of claim 1 , wherein the directional angle of each light-emitting diode chip is 146°.