Integrated active-matrix light emitting pixel arrays based devices

Abstract

Integrated active-matrix light emitting pixel arrays based displays and methods of fabricating the integrated displays are provided. One of the methods includes: forming a plurality of light emitting elements on a substrate, each of the light emitting elements including multiple semiconductor layers epitaxially grown on the substrate and being configured to emit light with a single color, integrating the light emitting elements formed on the substrate with a backplane device, such that each of the light emitting elements is bonded and conductively coupled to a respective pixel circuit in the backplane device, and then removing the substrate from the light emitting elements that remain integrated with the backplane device. Active-matrix multi-color pixel arrays can be formed by sequentially integrating different color light emitting element arrays on the backplane device or depositing different color phosphor or quantum dot materials on single color light emitting element arrays integrated on the backplane device.

What is claimed is: 
     
         1 . A method of fabricating an integrated device, comprising:
 forming a plurality of first light emitting elements on a first substrate, each of the first light emitting elements comprising first semiconductor layers epitaxially grown on the first substrate and being configured to emit light with a first color, the first semiconductor layers comprising a first conductive outer layer on a side of the first semiconductor layers further from the first substrate;   integrating the first light emitting elements formed on the first substrate with a backplane device having a plurality of pixel circuits by bonding the first conductive outer layers of the first light emitting elements with conductive outer layers of first pixel circuits in the plurality of pixel circuits such that each of the first light emitting elements is bonded and conductively coupled to a first pixel circuit in the backplane device, wherein the plurality of pixel circuits are conductively isolated from each other; and then   after integrating the first light emitting elements, removing the first substrate from the first light emitting elements that remain integrated with the backplane device.   
     
     
         2 . The method of  claim 1 , wherein integrating the first light emitting elements on the first substrate with the backplane device comprises:
 before the bonding, pretreating with plasma activation at least one of surfaces of the first conductive outer layers of the first light emitting elements or a surface of the backplane device comprising surfaces of the conductive outer layers of the first pixel circuits.   
     
     
         3 . The method of  claim 1 , wherein forming a plurality of first light emitting elements on a first substrate comprises:
 patterning a first light emitting structure formed on the first substrate to form the plurality of first light emitting elements, wherein the first light emitting structure comprises the first semiconductor layers epitaxially grown on the first substrate.   
     
     
         4 . The method of  claim 3 , wherein patterning a first light emitting structure formed on the first substrate to form the plurality of first light emitting elements comprises:
 patterning the first light emitting structure formed on the first substrate according to a pattern of the first pixel circuits in the backplane device, such that each of the first light emitting elements is aligned and bonded on top of the first pixel circuit in the backplane device.   
     
     
         5 . The method of  claim 1 , wherein integrating the first light emitting elements on the first substrate with the backplane device comprises:
 directly bonding surfaces of the first conductive outer layers of the first light emitting elements with surfaces of conductive outer layers of the first pixel circuits.   
     
     
         6 . The method of  claim 1 , further comprising:
 before the integrating, aligning the first light emitting elements with the first pixel circuits.   
     
     
         7 . The method of  claim 6 , wherein aligning the first light emitting elements with the first pixel circuits comprises:
 aligning the first light emitting elements on the first substrate with the first pixel circuits in a first region of the backplane device,   wherein integrating the first light emitting elements on the first substrate with the backplane device comprises:
 bonding the first light emitting elements on the first substrate with the first pixel circuits in the first region of the backplane device, and 
   wherein the method further comprises:
 bonding another plurality of first light emitting elements on another first substrate with respective another first pixel circuits in a second region of the backplane device, the second region being adjacent to the first region; and 
 removing the another first substrate from the another plurality of first light emitting elements that remain bonded on the backplane device. 
   
     
     
         8 . The method of  claim 1 , wherein removing the first substrate from the first light emitting elements comprises:
 scanning, by using a laser, an area on the first substrate such that the first light emitting elements in the area are separated from the first substrate and bonded on the backplane device; and   lifting off the first substrate from the first light emitting elements that remain bonded on the backplane device.   
     
     
         9 . The method of  claim 1 , wherein a size of the first light emitting element is no smaller than a size of the first pixel circuit. 
     
     
         10 . The method of  claim 1 , wherein each of the pixel circuits comprises a non-volatile memory including at least one transistor conductively coupled to a corresponding drive electrode that is a conductive outer layer of the pixel circuit, the corresponding drive electrodes in adjacent pixel circuits being separated by dielectric spacers, and
 wherein each of the first light emitting elements comprises a corresponding contact electrode as the first conductive outer layer, and   wherein each of the first light emitting elements is conductively coupled to a non-volatile memory in the first pixel circuit through a corresponding contact electrode and a corresponding drive electrode of the first pixel circuit.   
     
     
         11 . The method of  claim 1 , further comprising:
 forming a plurality of second light emitting elements on a second substrate, each of the second light emitting elements comprising second semiconductor layers epitaxially grown on the second substrate an being configured to emit light with a second color different from the first color, the second semiconductor layers comprising a second conductive outer layer on a side of the second semiconductor layers further from the second substrate;   integrating the second light emitting elements formed on the second substrate with the backplane device by bonding the second conductive outer layers of the second light emitting elements with conductive outer layers of second pixel circuits in the plurality of pixel circuits, such that each of the second light emitting elements is bonded and conductively coupled to a second pixel circuit that is adjacent to a corresponding first pixel circuit in the backplane device; and then   after integrating the second light emitting elements, removing the second substrate from the second light emitting elements that remain integrated with the backplane device, wherein each of the second light emitting elements is adjacent to a corresponding first light emitting element on the backplane device.   
     
     
         12 . The method of  claim 11 , wherein a height of each of the second light emitting elements formed on the second substrate is larger than or identical to a height of each of the first light emitting elements formed on the first substrate. 
     
     
         13 . The method of  claim 11 , wherein a distance between adjacent second light emitting elements on the backplane device is substantially identical to a distance between adjacent second pixel circuits in the backplane device, and
 wherein a distance between adjacent first and second light emitting elements is smaller than or identical to a distance between adjacent pixel circuits in the backplane device.   
     
     
         14 . The method of  claim 11 , further comprising:
 forming a plurality of third light emitting elements on a third substrate, each of the third light emitting elements comprising third semiconductor layers epitaxially grown on the third substrate and being configured to emit light with a third color that is different from the first color and the second color, the third semiconductor layers comprising a third conductive outer layer on a side of the third semiconductor layers further from the third substrate;   integrating the third light emitting elements formed on the third substrate with the backplane device by bonding the third conductive outer layers of the third light emitting elements with conductive outer layers of third pixel circuits in the plurality of pixel circuits, such that each of the third light emitting elements is bonded and conductively coupled to a third pixel circuit that is adjacent to a corresponding first pixel circuit and a corresponding second pixel circuit in the backplane device; and then   after integrating the third light emitting elements, removing the third substrate from the third light emitting elements that remain integrated with the backplane device, wherein each of the third light emitting elements on the backplane device is adjacent to a corresponding first light emitting element and a corresponding second light emitting element on the backplane device.   
     
     
         15 . The method of  claim 14 , wherein a height of each of the third light emitting elements formed on the third substrate is larger than or identical to a height of each of the second light emitting elements formed on the second substrate that is larger than or identical to a height of each of the first light emitting elements formed on the first substrate. 
     
     
         16 . The method of  claim 14 , wherein the first light emitting elements are conductively connected to the first pixel circuits to form first sub-pixels of active-matrix multi-color pixels,
 wherein the second light emitting elements are conductively connected to the second pixel circuits to form second sub-pixels of the active-matrix multi-color pixels,   wherein the third light emitting elements are conductively connected to the third pixel circuits to form third sub-pixels of the active-matrix multi-color pixels,   wherein each of the active-matrix multi-color pixels comprises a first sub-pixel having a first light emitting element and a first pixel circuit, a second sub-pixel having a second light emitting element and a second pixel circuit, and a third sub-pixel having a third light emitting element and a third pixel circuit, and   wherein the first, second, and third light emitting elements in each of the active-matrix multi-color pixels are adjacent and conductively isolated from each other, and the respective first, second, and third pixel circuits are adjacent and conductively isolated from each other.   
     
     
         17 . The method of  claim 16 , wherein each of the active-matrix multi-color pixels comprises a red light-emitting diode (LED), a green LED, and a blue LED. 
     
     
         18 . The method of  claim 14 , further comprising:
 filling an isolation material in gaps between adjacent first, second and third light emitting elements that remain integrated on the backplane device,   wherein the isolation material comprises an opaque and conductively isolated dielectric material.   
     
     
         19 . The method of  claim 18 , wherein each of the first, second, third light emitting elements comprises a first contact electrode as a conductive outer layer of the light emitting element and a second contact electrode formed on a buffer layer that is formed on a corresponding substrate, and
 wherein the method further comprises:
 planarizing the first, second, third light emitting elements with the isolation material filled in the gaps to remove the buffer layers to form a common surface with exposure of the second contact electrodes of the first, second, third light emitting elements. 
   
     
     
         20 . The method of  claim 19 , further comprising:
 forming a transparent conductive layer on the common surface to form a common electrode for the first, second, and third light emitting elements.   
     
     
         21 . A method of fabricating an integrated active-matrix multi-color pixel array based display, the method comprising:
 forming a plurality of light emitting elements on a semiconductor substrate, each of the light emitting elements comprises multiple semiconductor layers epitaxially grown on the semiconductor substrate and being configured to emit light with a first color, the semiconductor layers including one or more quantum well layers having Group III-V compounds between a first doped semiconductor layer as a first contact electrode and a second doped semiconductor layer as a second contact electrode;   integrating the light emitting elements on the semiconductor substrate with a backplane device to form a plurality of active-matrix light emitting pixels by conductively connecting the first contact electrode of each of the light emitting elements with a drive electrode of a respective pixel circuit in the backplane device, wherein the backplane device comprises at least one backplane having a plurality of pixel circuits that are conductively isolated from each other, each of the pixel circuits comprising a non-volatile memory conductively coupled to the drive electrode of the pixel circuit, wherein each of the active-matrix pixels comprises at least one of the light emitting element and at least one of the non-volatile memories conductively coupled to the at least one of the light emitting elements, then   removing the semiconductor substrate from the light emitting elements that remain integrated on the backplane device; and   forming an array of active-matrix multi-color display pixels by selectively depositing at least one phosphor film or quantum dots film on at least one light emitting element in each of the active-matrix light emitting pixels, the at least one phosphor film or quantum dots film being operable to emit a secondary light when excited by the light with the first color from the at least one light emitting element, wherein the secondary light has a second color different from the first color.   
     
     
         22 . The method of  claim 21 , further comprising:
 after removing the semiconductor substrate from the light emitting elements, forming first isolation spacers between adjacent light emitting elements, the first isolation spacers including an opaque conductively isolated dielectric material;   planarizing the light emitting elements with the first isolation spacers to expose the second contact electrodes of the light emitting elements and to form a common surface across the second contact electrodes of the light emitting elements;   depositing a transparent conductive layer on the common surface to form a common electrode for the light emitting elements integrated on the backplane device, wherein the at least one phosphor film or quantum dots film is selectively formed on the transparent conductive layer;   forming second isolation spacers between adjacent pixel elements of the active-matrix multi-color display pixels and on the transparent conductive layer, the second isolation spacers comprising the opaque conductively isolated dielectric material; and   forming a transparent protective layer on top of the active-matrix multi-color display pixels and the second isolation spacers.