Vertical solid state devices
A vertical current mode solid state device comprising a connection pad and side walls comprising a metal-insulator-semiconductor (MIS) structure, wherein leakage current effect of the vertical device is limited through the side walls by biasing the MIS structure.
1. A method of manufacturing a micro device, comprising:
providing two functional contacts and a gate conductive layer coupled to sidewalls of the micro device;
providing a semiconductor layer stack including an active layer;
mounting sidewalls on the semiconductor layer stack comprising an insulator, the gate conductive layer forming a continuous metal-insulator-semiconductor (MIS) structure with the semiconductor layer stack on a donor substrate, the MIS structure configured to modulate an internal electric field;
providing an electrode layer coupled to the gate conductive layer to apply a bias to the gate conductive layer during an operation of the micro device; and
providing a controller configured to dynamically adjust a bias condition of the gate conductive layer.
2. The method according to claim 1 , further comprising:
transferring the semiconductor layer stack with the MIS structure from the donor substrate to a system substrate.
3. The method according to claim 2 , further comprising:
providing a circuit layer on the system substrate;
providing a connection pad, comprising one of the two functional contacts, on the circuit layer connecting the semiconductor layer stack to the circuit layer through the connection pad;
connecting a second of the two functional contacts to the circuit layer through an opening in a first dielectric layer, wherein the first dielectric layer is deposited between the gate conductive layer and one of the two functional contacts.
4. The method according to claim 2 , further comprising surrounding the semiconductor layer stack with the gate conductive layer.
5. The method according to claim 2 , wherein the semiconductor layer stack comprises a micro-LED device.
6. A method of operating a micro device, the micro device comprising:
a semiconductor layer stack including an active layer;
two functional contacts and a gate conductive layer coupled to sidewalls of the micro device;
the semiconductor layer stack, wherein sidewalls comprise an insulator and the gate conductive layer forms a continuous metal-insulator-semiconductor (MIS) structure with the semiconductor layer stack;
the method comprising:
a) choosing a bias condition for the gate conductive layer to modulate an internal electric field of the micro device by applying a bias to the MIS structure, and reduce or eliminate an efficiency loss due to non-idealities, wherein the non-idealities comprise of a leakage current, non-radiative recombinations, an Auger recombination, a charge crowding or a charge imbalance, wherein the bias is applied through an electrode layer connected to the gate conductive layer during an operation of the micro device;
b) biasing the gate conductive layer, through a separate electrode, to modulate the internal electric field to reduce leakage current or non radiative recombination during operation of the active layer; and
c) providing a controller configured to adjust the bias of the gate conductive layer.
7. The method according to claim 6 , wherein the semiconductor layer stack comprises a micro-LED device; and step a) comprises biasing the gate conductive layer to limit a leakage current effect through sidewalls of the micro-LED device.
8. The method according to claim 6 , wherein the semiconductor layer stack comprises a micro-LED device; and step a) comprises biasing the gate conductive layer to reduce Auger recombination in the micro-LED device.
9. The method according to claim 6 , further comprising: providing the controller capable of biasing the gate conductive layer for modulating the internal field to limit the leakage current through the sidewalls and non-radiative recombination during operation of the micro device.
10. The method according to claim 6 , wherein the semiconductor layer stack includes sloped walls, on which the MIS structure is mounted.
11. The structure of claim 1 , wherein the micro device is formed by patterning or by selective growth.