Transfer-bonding method for the light emitting device and light emitting device array

Abstract

A transfer-bonding method for light emitting devices including following steps is provided. A plurality of light emitting devices is formed over a first substrate and is arranged in array, wherein each of the light emitting devices includes a device layer and a sacrificial pattern sandwiched between the device layer and the first substrate. A protective layer is formed over the first substrate to selectively cover parts of the light emitting devices, and other parts of the light emitting devices are uncovered by the protective layer. The device layers uncovered by the protective layer are bonded with a second substrate. The sacrificial patterns uncovered by the protective layer are removed, so that parts of the device layers uncovered by the protective layer are separated from the first substrate and are transfer-bonded to the second substrate.

1 . A transfer-bonding method for light emitting devices comprising:
 forming a plurality of light emitting devices arranged in array over a first substrate, wherein each of the light emitting devices comprises a device layer and a sacrificial pattern sandwiched between the device layer and the first substrate;   forming a protective layer over the first substrate to selectively cover the light emitting devices, wherein parts of the light emitting devices are uncovered by the protective layer;   bonding the device layers uncovered by the protective layer with a second substrate; and   removing the sacrificial patterns uncovered by the protective layer, so that parts of the device layers are separated from the first substrate and are transfer-bonded to the second substrate.   
     
     
         2 . The transfer-bonding method for light emitting devices as recited in  claim 1 , wherein forming light emitting devices over the first substrate comprises:
 forming a first type doped semiconductor layer, a light emitting layer and a second type doped semiconductor layer on a growth substrate;   forming a sacrificial layer on the first substrate;   bonding the second type doped semiconductor layer with the sacrificial layer;   separating the first type doped semiconductor layer from the growth substrate;   patterning the first type doped semiconductor layer, the light emitting layer, the second type doped semiconductor layer, and the sacrificial layer to form a plurality of first type doped semiconductor patterns, a plurality of light-emitting patterns, a plurality of second type doped semiconductor patterns, and the sacrificial patterns; and   forming a plurality of electrodes over the first type semiconductor patterns.   
     
     
         3 . The transfer-bonding method for light emitting devices as recited in  claim 2 , wherein the sacrificial layer comprises a patterned sacrificial layer. 
     
     
         4 . The transfer-bonding method for light emitting devices as recited in  claim 1 , wherein the second substrate comprises a circuit substrate, the circuit substrate has a plurality of bonding pads and a plurality of conductive bumps located over the bonding pads, the device layers uncovered by the protective layer are bonded with the bonding pads through parts of the conductive bumps, and parts of the device layers are transfer-bonded to the circuit substrate when the sacrificial patterns uncovered by the protective layer are removed. 
     
     
         5 . The transfer-bonding method for light emitting devices as recited in  claim 4  further comprising transfer-bonding the device layers capable of emitting different colored lights to the circuit substrate by a method, the method comprises:
 forming a plurality of light emitting devices arranged in array over a first substrate, wherein each of the light emitting devices comprises a device layer and a sacrificial pattern sandwiched between the device layer and the first substrate; 
 forming a protective layer over the first substrate to selectively cover the light emitting devices, wherein parts of the light emitting devices are uncovered by the protective layer; 
 bonding the device layers uncovered by the protective layer with a second substrate; and 
 removing the sacrificial patterns uncovered by the protective layer, so that parts of the device layers are separated from the first substrate and are transfer-bonded to the second substrate. 
 
     
     
         6 . The transfer-bonding method for light emitting devices as recited in  claim 5 , wherein the device layers capable of emitting different colored lights have different thicknesses, and the conductive bumps bonded with the device layers capable of emitting different colored lights have different heights, such that top surfaces of the device layers capable of emitting different colored lights are located on a same level of height. 
     
     
         7 . The transfer-bonding method for light emitting devices as recited in  claim 1  further comprising:
 forming a common electrode on the device layers over the second substrate. 
 
     
     
         8 . The transfer-bonding method for light emitting devices as recited in  claim 7  further comprising:
 forming a black matrix on the common electrode, wherein the black matrix has a plurality of openings, and each of the openings is respectively located above at least one of the device layers. 
 
     
     
         9 . The transfer-bonding method for light emitting devices as recited in  claim 1  further comprising:
 forming a micro-lens array, wherein the micro-lens array comprises a plurality of micro-lenses arranged in array, and each of the micro-lenses is respectively located above at least one of the device layers. 
 
     
     
         10 . The transfer-bonding method for light emitting devices as recited in  claim 1 , wherein forming the light emitting devices over the first substrate comprises:
 forming a first type doped semiconductor layer, a light emitting layer and a second type doped semiconductor layer on the growth substrate;   forming a plurality of electrodes over the second type doped semiconductor layer;   forming a sacrificial layer on the first substrate;   bonding the sacrificial layer with the second type doped semiconductor layer and the electrodes;   separating the first type doped semiconductor layer from the growth substrate; and   patterning the first type doped semiconductor layer, the light emitting layer, the second type doped semiconductor layer, and the sacrificial layer to form a plurality of first type doped semiconductor patterns, a plurality of light-emitting patterns, a plurality of second type doped semiconductor patterns, and the sacrificial patterns.   
     
     
         11 . The transfer-bonding method for light emitting devices as recited in  claim 10 , wherein the sacrificial layer comprises a patterned sacrificial layer. 
     
     
         12 . The transfer-bonding method for light emitting devices as recited in  claim 10 , wherein the second substrate comprises a stamp mold, the stamp mold has a plurality of protrusions, the light emitting devices uncovered by the protective layer are bonded with the protrusions, and when the sacrificial patterns uncovered by the protective layer are removed, parts of the device layers are transfer-bonded to the stamp mold. 
     
     
         13 . The transfer-bonding method for light emitting devices as recited in  claim 12  further comprising:
 bonding the parts of the device layers transfer-bonded to the stamp mold with a circuit substrate to further transfer-bond the device layers to a circuit substrate, wherein the circuit substrate has a plurality of bonding pads and a plurality of conductive bumps located over the bonding pads, and the electrodes are bonded with the bonding pads through parts of the conductive bumps. 
 
     
     
         14 . The transfer-bonding method for light emitting devices as recited in  claim 13  further comprising transfer-bonding the device layers capable of emitting different colored lights to the circuit substrate by a method, the method comprises:
 forming a plurality of light emitting devices arranged in array over a first substrate, wherein each of the light emitting devices comprises a device layer and a sacrificial pattern sandwiched between the device layer and the first substrate; 
 forming a protective layer over the first substrate to selectively cover the light emitting devices, wherein parts of the light emitting devices are uncovered by the protective layer; 
 bonding the device layers uncovered by the protective layer with a second substrate; and 
 removing the sacrificial patterns uncovered by the protective layer, so that parts of the device layers are separated from the first substrate and are transfer-bonded to the second substrate; and 
 bonding the parts of the device layers transfer-bonded to the stamp mold with a circuit substrate to further transfer-bond the device layers to a circuit substrate, wherein the circuit substrate has a plurality of bonding pads and a plurality of conductive bumps located over the bonding pads, and the electrodes are bonded with the bonding pads through parts of the conductive bumps. 
 
     
     
         15 . The transfer-bonding method for light emitting devices as recited in  claim 14 , wherein the device layers capable of emitting different colored lights have different thicknesses, the conductive bumps bonded with the device layers capable of emitting different colored lights have different heights, such that top surfaces of the device layers capable of emitting different colored lights are located on different level of heights. 
     
     
         16 . A light emitting device array comprising:
 a circuit substrate having a plurality of bonding pads and a plurality of conductive bumps located over the bonding pads; and   a plurality of device layers capable of emitting different colored lights electrically connected with the circuit substrate through the conductive bumps and the bonding pads, wherein the device layers capable of emitting different colored lights have different thicknesses, the conductive bumps bonded with the device layers capable of emitting different colored lights have different heights, such that top surfaces of the device layers capable of emitting different colored lights are located on a same level of height.   
     
     
         17 . The light emitting device array as recited in  claim 16  further comprising:
 a common electrode located on the device layers. 
 
     
     
         18 . The light emitting device array as recited in  claim 17  further comprising:
 a black matrix located on the common electrode, wherein the black matrix has a plurality of openings, and each of the openings is respectively located above one of the device layers. 
 
     
     
         19 . The light emitting device array as recited in  claim 16  further comprising:
 a micro-lens array comprising a plurality of micro-lenses arranged in array, and each of the micro-lenses is respectively located above one of the device layers.