LIGHT-EMITTING ELEMENT AND THE MANUFACTURING METHOD THEREOF
A light-emitting element comprises: a light-emitting stack configured to emit light; and a transparent substrate comprising an upper surface on which the light-emitting stack is formed, a bottom surface opposite to the upper surface, and a side surface connecting the upper surface with the bottom surface, wherein the side surface comprises a first arc portion, a second arc portion, and a transition portion between the first arc portion from and second arc portion.
1 . A light-emitting element, comprising:
a light-emitting stack configured to emit light; and
a transparent substrate comprising an upper surface on which the light-emitting stack is formed, a bottom surface opposite to the upper surface, and a side surface connecting the upper surface with the bottom surface, wherein the side surface comprises a first arc portion, a second arc portion, and a transition portion between the first arc portion and the second arc portion.
2 . The light-emitting element according to claim 1 , wherein the first arc portion is closer to the bottom surface than the second arc portion.
3 . The light-emitting element according to claim 2 , wherein the transition portion is the outmost part of the side surface in a lateral direction.
4 . The light-emitting element according to claim 3 , wherein the bottom surface comprises a first width, the transition portion of the side surface comprises a second width greater than the first width, and the upper surface comprises a third width smaller than the second width in a cross-sectional view.
5 . The light-emitting element according to claim 3 , further comprising a reflective structure conformably formed on the bottom surface and the first arc portion of the side surface.
6 . The light-emitting element according to claim 5 , wherein the reflective structure comprises a DBR.
7 . The light-emitting element according to claim 1 , wherein the transition portion comprises a flat surface.
8 . The light-emitting element according to claim 1 , wherein the transition portion comprises a vertex.
9 . The light-emitting element according to claim 3 , wherein the side surface further comprises a plurality of arc portions and a plurality of transition portions separating the plurality of arc portions from each other.
10 . The light-emitting element according to claim 1 , wherein the first arc portion comprises a curvature different from that of the second arc portion.
11 . The light-emitting element according to claim 1 , wherein each of the first arc portion and the second arc portion comprises a negative curvature.
12 . The light-emitting element according to claim 1 , wherein the transparent substrate is single-crystalline, and the light-emitting stack is an epitaxial structure.
13 . A method for manufacturing a light-emitting element, comprising the steps of:
providing a wafer comprising an upper surface and a bottom surface;
forming a light-emitting stack on the upper surface of the wafer;
cutting the wafer from the bottom surface of the wafer to form a first arc portion by a water-jet laser having a first beam size;
cutting the wafer from the upper surface of the wafer to form a second arc portion by the water-jet laser having a second beam size; and
dividing the wafer and the light-emitting stack into a plurality of light-emitting dies, wherein one of the light-emitting dies comprises a side surface having the first arc portion and the second arc portion.
14 . The method according to claim 13 , further comprising forming a plurality of trenches for dividing the light-emitting stack into multiple light-emitting blocks and exposing the upper surface of the wafer before cutting the wafer by the water jet laser.
15 . The method according to claim 13 , wherein the wafer comprises a plurality of thinned portions after being cut by the water jet laser, and the method further comprises breaking the thinned portions to divide the wafer into the plurality of light-emitting elements.
16 . The method according to claim 14 , wherein the step of dividing the wafer and the light-emitting stack into a plurality of light-emitting dies comprises continuing cutting the wafer by the water-jet laser to penetrate through the wafer completely.
17 . The method according to claim 13 , wherein the water-jet laser comprises a water jet and a laser traveling in the water jet.
18 . The method according to claim 13 , further comprising cutting the wafer from the bottom surface of the wafer to form a third arc portion by the water-jet laser having a third beam size different from the first beam size.
19 . The method according to claim 18 , wherein the first beam size is bigger than one of the second beam size and the third beam size.
20 . The method according to claim 13 , further comprising forming a reflective structure on the bottom surface and the first arc portion before dividing the wafer and the light-emitting stack into a plurality of light-emitting dies.