Patterned substrate and light emitting diode wafer
A patterned substrate includes a main base and a plurality of patterned structures. The main base has at least one device-disposed region and a cutting region surrounding the device-disposed region. The patterned structures are integratedly formed with the main base, and only distributed in the cutting region of the main base. The patterned structures are separated from each other.
1. A patterned substrate, comprising:
a main base, having at least one device-disposed region and a cutting region surrounding the device-disposed region; and
a plurality of patterned structures, integrally formed with the main base, and only distributed in the cutting region of the main base, wherein the patterned structures are separated from each other;
wherein a surface roughness of the cutting region is greater than a surface roughness of the device-disposed region.
2. The patterned substrate as recited in claim 1 , wherein the patterned structures protrude from the main base, and a shape of the patterned structures comprises a pyramid, a cone, a ball or a trapezoid.
3. The patterned substrate as recited in claim 1 , wherein the patterned structures are embedded in the main base, and a shape of the patterned structures comprises a concave-pyramid, a concave-cone, a concave-ball or a concave-trapezoid.
4. The patterned substrate as recited in claim 1 , wherein a width of the device-disposed region is between 1 μm and 15 μm.
5. The patterned substrate as recited in claim 4 , wherein the width of the device-disposed region is defined as a distance between two patterned structures respectively located at opposite sides of the device-disposed region and adjacent to the device-disposed region.
6. The patterned substrate as recited in claim 1 , wherein a ratio of a width to a height of each of the patterned structures is between 0.8 and 1.5.
7. The patterned substrate as recited in claim 1 , wherein each of the patterned structures has a roughen surface.
8. A light emitting diode wafer, comprising:
a patterned substrate, the patterned substrate comprising:
a main base, having a plurality of device-disposed regions and a cutting region surrounding the device-disposed regions; and
a plurality of patterned structures, integrally formed with the main base, and only distributed in the cutting region of the main base, wherein the patterned structures are separated from each other; and
an epitaxial layer, disposed on the patterned substrate, wherein the patterned structures are located between the main base and the epitaxial layer;
wherein a surface roughness of the cutting region is greater than a surface roughness of the device-disposed region.
9. The light emitting diode wafer as recited in claim 8 , wherein the patterned structures protrude from the main base and a shape of the patterned structures comprises a pyramid, a cone, a ball or a trapezoid.
10. The light emitting diode wafer as recited in claim 8 , wherein the patterned structures are embedded in the main base, and a shape of the patterned structures comprises a concave-pyramid, a concave-cone, a concave-ball or a concave-trapezoid.
11. The light emitting diode wafer as recited in claim 8 , wherein a width of each of the device-disposed regions is between 1 μm and 15 μm, and a ratio of a width to a height of each of the patterned structures is between 0.8 and 1.5.
12. The light emitting diode wafer as recited in claim 8 , wherein each of the patterned structures has a roughen surface.
13. The light emitting diode wafer as recited in claim 8 , wherein the epitaxial layer has a plurality of sub-epitaxial structures, and the sub-epitaxial structures are separated from each other and correspondingly located on the device-disposed regions.
14. The light emitting diode wafer as recited in claim 13 , wherein a ratio of a width to a height of each of the patterned structures is between 0.2 and 1.
15. The light emitting diode wafer as recited in claim 13 , further comprising:
a buffer layer, located between the patterned substrate and the epitaxial layer, wherein the buffer layer has a plurality of buffer portions separated from each other, the buffer portions are correspondingly located on the device-disposed regions, and the sub-epitaxial structures are respectively formed on the buffer portions.
16. The light emitting diode wafer as recited in claim 15 , wherein each of the buffer portions has a bottom surface in contact with the main base and a top surface in contact with each of the sub-epitaxial structures, and an area of the bottom surface is less than an area of the top surface.