VERTICAL SOLID-STATE DEVICES
As the pixel density of optoelectronic devices becomes higher, and the size of the optoelectronic devices becomes smaller, the problem of isolating the individual micro devices becomes more difficult. A method of fabricating an optoelectronic device, which includes an array of micro devices, comprises: forming a device layer structure including a monolithic active layer on a substrate; forming an array of first contacts on the device layer structure defining the array of micro devices; mounting the array of first contacts to a backplane comprising a driving circuit which controls the current flowing into the array of micro devices; removing the substrate; and forming an array of second contacts corresponding to the array of first contacts with a barrier between each second contact.
1 . An optoelectronic device, including an array of micro devices, the optoelectronic device comprising:
a backplane comprising a driving circuit which controls the current flowing into the micro devices, and an array of pads connected to the driving circuit;
an array of bottom contacts electrically connected to the pads of the driving circuit;
a device layer structure including a monolithic active layer;
at least one top contact for the array of micro devices; and
a common top electrode connected to all of the top contacts.
2 . The device according to claim 1 , wherein the at least one top contact comprises an array of top contacts corresponding to the bottom contacts.
3 . The device according to claim 1 , wherein the device layer structure includes a top conductive layer, a bottom conductive layer, and the monolithic active layer therebetween.
4 . The device according to claim 3 , wherein the array of top contacts comprises an array of top conductive layer sections corresponding to the array of top contacts extending from the top conductive layer.
5 . The device according to claim 4 , wherein the array of top contacts includes a barrier between each top contact
6 . The device according to claim 5 , further comprising an array of colour conversion elements on top of the common top electrode, corresponding to the array of top contacts with a bank structure between each colour conversion element.
7 . The device according to claim 6 , wherein the bank structure and the barrier comprise a same combined bank structure; and wherein the common top electrode includes recesses for receiving the combined bank structures.
8 . The device according to claim 3 , wherein the array of top contacts includes a barrier between each top contact; and wherein each barrier comprises an array of top conductive layer sections extending from the top conductive layer; and further comprising a dielectric layer between the top conductive layer sections and the common top electrode.
9 . The device according to claim 8 , further comprising an array of colour conversion elements, corresponding to the array of top contacts between the array of top conductive layer sections.
10 . The device according to claim 9 , wherein the common top electrode includes an array of raised sections corresponding to the array of bottom contacts and extending between the top conductive layer sections.
11 . The device according to claim 10 , further comprising colour conversion elements between each of the raised sections and the top conductive layer.
12 . The device according to claim 3 , further comprising a dielectric material between each of the bottom contacts.
13 . The device according to claim 12 , wherein the dielectric material extends into recesses in the bottom conductive layer between raised sections extending from the bottom conductive layer in an array corresponding to the bottom contacts.
14 . The device according to claim 3 , wherein the array of bottom contacts includes an array of raised sections in the bottom conductive layer corresponding to the array of bottom contacts.
15 . The device according to claim 14 , wherein the array of raised sections includes an array of island contacts, each less than ½ a size of one of the pads, whereby a plurality of island contacts contact each pad.
16 . The device according to claim 3 , wherein the array of bottom contacts includes an array of island contacts between the pads and the bottom conductive layer, each island contact less than ½ a size of one of the pads, whereby a plurality of island contacts contact each pad.
17 . A method of fabricating an optoelectronic device, including an array of micro devices, comprising:
forming a device layer structure, including a monolithic active layer, on a substrate;
forming an array of first contacts on the device layer structure defining the array of micro devices;
mounting the array of first contacts to a backplane comprising a driving circuit which controls the current flowing into the array of micro devices, and an array of pads connected to the driving circuit;
removing the substrate; and
forming a second contact layer.
18 . The method according to claim 17 , wherein forming the second contact layer comprises forming an array of second contacts corresponding to the array of first contacts.
19 . The method according to claim 18 , wherein the step of forming the device layer structure includes:
forming a second conductive layer on the substrate,
forming the monolithic active layer on the first conductive layer; and
forming a first conductive layer on the active layer.
20 . The method according to claim 19 , wherein the step of forming the array of second contacts comprises forming an array of second conductive layer sections extending from the second conductive layer.
21 . The method according to claim 20 , wherein the step of forming the array of second conductive layer sections comprising etching the second conductive layer to form the array of second conductive layer sections.
22 . The method according to claim 20 , wherein the step of forming the array of second conductive layer sections comprising laser ablating the second conductive layer to form the array of second conductive layer sections.
23 . The method according to claim 20 , wherein the step of forming the array of second conductive layer sections comprising doping sections of the second conductive layer to form the array of second conductive layer sections.
24 . The method according to claim 18 , wherein forming the array of second contacts includes forming a barrier between each second contact
25 . The method according to claim 24 , further comprising:
forming a common electrode on top of the second array of contacts; and
forming an array of colour conversion elements on top of the common electrode, corresponding to the second array of contacts with a bank structure between each colour conversion element.
26 . The method according to claim 25 , wherein forming the bank structure and the barrier comprise forming a same combined bank structure; and wherein the common top electrode includes recesses for receiving the combined bank structures.
27 . The method according to claim 24 , wherein forming the barrier comprises forming an array of second conductive layer sections extending from the second conductive layer; and further comprising:
forming a common top electrode in contact with the array of second contacts; and
forming a dielectric layer between the second conductive layer sections and the common top electrode.
28 . The method according to claim 27 , further comprising forming an array of colour conversion elements, corresponding to the array of second contacts between the array of second conductive layer sections.
29 . The method according to claim 27 , wherein forming the common top electrode includes forming an array of raised sections corresponding to the array of second contacts and extending between the second conductive layer sections.
30 . The method according to claim 29 , further comprising depositing colour conversion elements between each of the raised sections and the second conductive layer.
31 . The method according to claim 19 , further comprising depositing a dielectric material between each first contact.
32 . The method according to claim 31 , further comprising forming recessing in the first conductive layer into which the dielectric material extends.
33 . The method according to claim 19 , wherein the step of forming the array of first contacts comprises forming an array of first conductive layer sections extending from the first conductive layer.
34 . The method according to claim 33 , wherein the step of forming the array of first conductive layer sections comprising etching the first conductive layer to form the array of first conductive layer sections.
35 . The method according to claim 33 , wherein the step of forming the array of first conductive layer sections comprising laser ablating the first conductive layer to form the array of first conductive layer sections.
36 . The method according to claim 33 , wherein the step of forming the array of first conductive layer sections comprising doping sections of the first conductive layer to form the array of first conductive layer sections.
37 . The method according to claim 33 , wherein forming the array of first conductive layer sections includes forming an array of island contacts, each less than ½ a size of one of the pads, whereby a plurality of island contacts contact each pad.
38 . The method according to claim 19 , wherein forming the array of first contacts includes forming an array of island contacts on the first conductive layer, each island contact less than ½ a size of one of the pads, whereby a plurality of island contacts contact each pad.
39 . The method according to claim 38 , wherein the step of forming the array of first contacts further comprises forming an array of first conductive layer sections extending from the first conductive layer.
40 . The method according to claim 39 , wherein each of the first conductive layer sections comprises a width substantially the same as each island contact.