Display device and method of fabricating the same
There is provided a display device. The display device includes a plurality of semiconductor elements disposed on a substrate; a plurality of LEDs disposed on the plurality of semiconductor elements and electrically connected to the plurality of semiconductor elements, respectively; and a plurality of reflectors disposed above the semiconductor elements and each located between every two of the LEDs. The plurality of LEDs may include a plurality of light-emitting layers disposed on the plurality of semiconductor elements, and a common electrode disposed on the plurality of light-emitting layers. The reflectors are disposed between the LEDs, so that light emitted from LEDs does not travel toward the side portions of the LEDs but toward the above of the substrate, thereby improving the light extraction efficiency and suppressing color mixture.
1. A method of fabricating a display device, the method comprising:
forming a plurality of semiconductor elements on a first substrate;
forming an epitaxial layer on a second substrate;
bonding the first substrate and the second substrate with the plurality of semiconductor elements of the first substrate facing the epitaxial layer of the second substrate;
separating the second substrate from the epitaxial layer;
etching parts of the epitaxial layer to form a plurality of second semiconductor layers, a plurality of light-emitting layers under the plurality of second semiconductor layers, and a plurality of first semiconductor layers under the plurality of light-emitting layers;
forming a plurality of reflectors between the plurality of light-emitting layers; and
forming a common electrode covering the plurality of second semiconductor layers and the plurality of reflectors.
2. The method of claim 1 , wherein the forming the plurality of semiconductor elements on the first substrate comprises forming a first metal layer on the semiconductor elements,
wherein the forming the epitaxial layer on the second substrate comprises,
forming a second semiconductor material layer on the second substrate;
forming a light-emitting material layer on the second semiconductor material layer;
forming a first semiconductor material layer on the light-emitting material layer; and
forming a second metal layer on the first semiconductor material layer, and
wherein the bonding the first substrate and the second substrate comprises electrically connecting the first metal layer of the first substrate with the second metal layer of the second substrate.
3. The method of claim 2 , wherein the separating the second substrate from the epitaxial layer further comprises processing a surface of the second semiconductor material layer that is exposed after the second substrate is separated, and wherein a thickness of the second semiconductor material layer after separating the second substrate is smaller than a thickness of the second semiconductor material layer before separating the second substrate.
4. The method of claim 2 , wherein the etching parts of the epitaxial layer comprises:
forming a protective layer and a photoresist sequentially on the second semiconductor material layer;
etching parts of the second semiconductor material layer, the light-emitting material layer, the first semiconductor material layer and the second metal layer that do not overlap with the photoresist to form the second semiconductor layer, the light-emitting layers and the first semiconductor layers;
etching parts of the first metal layer that do not overlap with the photoresist to form a first bonding electrode; and
removing the protective layer and the photoresist on the second semiconductor layers.
5. The method of claim 2 , wherein the forming the plurality of semiconductor elements on the first substrate further comprises:
forming a planarization layer to provide a flat surface over the plurality of semiconductor elements; and
forming a plurality of connection electrodes on an upper surface of the planarization layer, the plurality of connection electrodes being electrically connected to the plurality of semiconductor elements, respectively, and
wherein the first metal layer is formed on the planarization layer and the plurality of connection electrodes.
6. The method of claim 5 , wherein the etching parts of the epitaxial layer comprises:
etching parts of the epitaxial layer that do not overlap with the plurality of connection electrodes.
7. The method of claim 1 , wherein the forming the plurality of reflectors comprises:
forming a reflective layer covering side portions of the plurality of second semiconductor layers, the plurality of light-emitting layers and the plurality of first semiconductor layers, and an upper surface of the plurality of second semiconductor layers;
etching parts of the reflective layer to open upper surfaces of the plurality of second semiconductor layers and form the plurality of reflectors, and
wherein the forming the common electrode comprises forming the common electrode covering the upper surfaces of the plurality of second semiconductor layers and upper surfaces of the plurality of reflectors.
8. The method of claim 7 , further comprising:
forming a plurality of light-blocking layers on the common electrode and overlapping the reflectors, respectively; and
forming a plurality of light conversion layers on the common electrode overlapping the LEDs, respectively,
wherein each of the plurality of light conversion layers is disposed between every two of the light-blocking layers.
9. The method of claim 8 , further comprising:
forming a plurality of color filters on the plurality of light conversion layers, respectively.