KR20130008224A - Method for manufacturing gan led device and gan led device manufactured by the same - Google Patents

Abstract

PURPOSE: A method for manufacturing a GaN LED device and a GaN LED device manufactured by the same are provided to easily verify a nerve circuit by using an LED array. CONSTITUTION: A gallium nitride light emitting diode element is formed on a sacrificial substrate(100). A gallium nitride light emitting diode element is chemically separated from the sacrificial substrate. A silicon oxide layer(200) is laminated on the sacrificial substrate. A patterning process is performed on the silicon oxide layer. A first gallium nitride film(201a) is grown up in a space between silicon oxide layers.

Description

Method for manufacturing a flexible gallium nitride light emitting diode device and a flexible gallium nitride light emitting diode device manufactured according to the present invention

The present invention relates to a method of manufacturing a flexible gallium nitride light emitting diode (GaN LED) device and a flexible gallium nitride light emitting diode device manufactured according to the present invention, and more particularly, it can be used in a narrow space through light weight, biotransportability, size control In particular, the present invention relates to a method for manufacturing a flexible gallium nitride light emitting diode (GaN LED) device which is very useful in photoelectricity, and a flexible gallium nitride light emitting diode device manufactured accordingly.

Photoelectricity is a disciplined technology that combines optics and genetics, developed and developed in the lab of Professor Deisseroth at Stanford University.

Photogenetics is a cutting-edge technology that regulates nerve cells with light, using viral vectors to express protein genes in cell membranes, such as channel-dodosin 2 (ChR2: Reacting to blue light emitted by GaN). Thus stimulating or inhibiting nerve cells. This photogenetics is a new technology that can be applied to the treatment of Parkinson's, epilepsy and body neural circuits, which overcomes the limitations of electrostimulation, which has not been able to selectively stimulate or inhibit cells. The spatio-temporal resolution of μm makes it a good tool for neural network analysis. In this case, the neurons in the light-controlled brain transmit information by the interaction of electrical signals, and measure these electrical signals directly from the neurons using tiny electrodes to see how these neural circuits work. have.

In addition, microelectrode array (MEA) is a microelectrode array (MEA) in which micro electrodes having a microscopic size are formed in an array form. In this case, neurons are inserted into the body environment in vivo and respond to light. Record the change in action potential at). In order to increase the spatial sophistication of electrodes in optogenetics, optical fibers, which are light sources for stimulating nerve cells, and optodes integrating electrodes adjacent to each other have been continuously studied. However, since the conventional brain implant metal electrode is mainly formed on a rigid substrate such as silicon in the form of a probe for mounting in a curved and narrow position of the brain, it is impossible to record an electrical signal of a large area of nerve cells, and a desired position. It is not easy to attach it to the body and damages the brain, so a flexible light source that can bend can stimulate the brain without damaging it, and an array of light sources can produce a specific pattern of stimulation to the brain. Can give Furthermore, if the light source is driven by a flexible battery implanted inside the living body, or if the battery becomes a secondary battery and is charged with energy in the human body by a nanogenerator in the living body, the experiment is performed without an external connection or additional surgery. More active activities can be guaranteed in the long run for animals or patients.

Accordingly, an object of the present invention is to provide a method for manufacturing a light emitting diode (LED) device and a flexible light emitting diode (LED) device for photoelectric stimulation based on flexible GaN inorganic materials.

In order to solve the above problems, the present invention provides a method for manufacturing a flexible gallium nitride light emitting diode device, the method comprising the steps of manufacturing a gallium nitride light emitting diode device on a sacrificial substrate; And chemically separating the gallium nitride light emitting diode device from the sacrificial substrate, wherein the chemical separation is performed by chemically removing the sacrificial layer between the sacrificial substrate and the gallium nitride light emitting diode device.

In one embodiment of the present invention, the method comprises: depositing a silicon oxide layer on a sacrificial substrate; Patterning the stacked silicon oxide layers and forming a plurality of spaced apart silicon oxide layer rows; Growing a first gallium nitride layer in a space between the plurality of silicon oxide layers; Stacking a second gallium nitride layer on the silicon oxide layer and the first gallium nitride layer; Forming a gallium nitride device layer including n-gallium nitride layers / light emitting layers / p-gallium nitride layers sequentially stacked on the stacked second gallium nitride layers; Patterning the formed gallium nitride device layer to form a plurality of unit gallium nitride light emitting diode devices; after removing the silicon oxide layer on the sacrificial substrate, transferring the formed plurality of unit gallium nitride light emitting diode devices to a plastic substrate And the silicon oxide layer removal is performed in a chemical manner.

In an embodiment of the present invention, the gallium nitride light emitting diode device has a structure in which a plurality of unit light emitting diode devices form an array, and the method includes the n-gallium nitride layer and the p-gallium nitride layer after the gallium nitride device layer stacking step. Exposing to the outside; Forming a metal contact on each of the n-gallium nitride layer and the p-gallium nitride layer; And forming a first metal line connecting the metal contact on the n-gallium nitride layer and a second metal line connecting the metal contact on the p-gallium nitride layer.

In an embodiment of the present invention, the first gallium nitride layer growth is performed in a horizontal overgrowth manner during epitaxy.

The present invention, in order to solve the above another problem, a flexible gallium nitride light emitting diode device, the device is a plastic substrate; A gallium nitride light emitting diode unit device provided on the substrate and including a n-gallium nitride layer / light emitting layer / p-gallium nitride layer sequentially stacked; A metal contact laminated on the n-gallium nitride layer and the p-gallium nitride layer of the gallium nitride light emitting diode unit device; A first metal line and a second metal line connecting the metal contacts stacked on the n-gallium nitride layer and the p-gallium nitride layer of the gallium nitride light emitting diode unit device, respectively; And a transparent insulating layer laminated on the first metal line and the second metal line.

In one embodiment of the present invention, the ends of the first metal line and the second metal line are exposed between the transparent insulating layer, and the transparent insulating layer is provided between the first metal line and the second metal line. In addition, the first metal line and the second metal line connect gallium nitride light emitting diode unit devices of different species and columns.

The present invention also relates to an optoelectronic photonic device comprising the above-described flexible gallium nitride light emitting diode device, wherein the optical device includes a microelectrode array including a plurality of electrode lines stacked on a transparent insulating layer on the flexible gallium nitride light emitting diode device. The microelectrode array is provided to correspond to each unit flexible gallium nitride light emitting diode device, and the microelectrode array detects a change in activity potential of nerve cells reacted by light generated by the gallium nitride light emitting diode device. .

The present invention provides a method for analyzing neurons using a microelectrode array of the photoelectric genetic device, and generating light from the gallium nitride light emitting diode device of the optical photoelectric device described above. Stimulating the living body; And it provides a light stimulation method using a photoelectric device for photoelectrics, characterized in that for measuring the action potential change of the neurons in response to the generated light with the microelectrode array.

The flexible GaN LED device according to the present invention has a cortical cortex (cognition, thinking, language, memory, etc., located under the spherical skull or skull bone, especially Parkinson's disease is a symptom caused by nerve cells located on the surface. Implantable into the human body of a tortuous surface. In addition, it is composed of a plurality, each of the light on-off stimulation of the nerve cells in various areas through the LED array that is independently turned on / off facilitates the identification of neural circuits.

1 to 29 are views illustrating a method of manufacturing a flexible GaN LED device according to the present invention.
30 to 32 are views illustrating a method of manufacturing an optoelectric optical device according to an embodiment of the present invention.
FIG. 33 is a schematic diagram illustrating a pattern stimulus using the flexible LED arrays 800a and 800b according to an embodiment of the present invention, and a method of reading the same into a MEA 800c.
34 is a view for explaining an example of the use of the photoelectric device for photoelectrics according to the present invention.

Hereinafter, the present invention will be described in detail with reference to preferred embodiments and drawings. However, the following embodiments are provided as examples to ensure that the spirit of the present invention to those skilled in the art to fully convey. Therefore, the present invention is not limited to the embodiments described below, but may be embodied in other forms. In the drawings, the width, length, thickness, etc. of the components may be exaggerated for convenience. Like numbers refer to like elements throughout.

In addition, all drawings attached to this specification are interpreted in the form of sectional drawing which cut | disconnected the whole plan view and partial cross section A-A '.

Plastic substrates are to be interpreted herein to include any and all substrates having flexibility, ie, flexible properties, more specifically meaning flexible polymer substrates.

1 to 31 are views illustrating a method of manufacturing a flexible gallium nitride light emitting diode (GaN LED) device according to the present invention.

Referring to FIG. 1, a sapphire substrate 100 is disclosed as a sacrificial substrate.

Referring to FIG. 2, a silicon oxide layer 200 is stacked on the sapphire substrate 100.

Referring to FIG. 3, after the photoresist layer 300 is stacked on the silicon oxide layer 200, the mask layer 301 for patterning the photoresist layer 300 is the photoresist layer 300. Laminated onto and patterned.

Referring to FIG. 4, the photoresist layer 300 exposed between the mask layers 301 is etched, and the mask layer 301 is removed to have a predetermined length and a plurality of columnar silicon spaced apart from each other. The oxide layer 200 is exposed between the photoresist layers 300.

Referring to FIG. 5, a plurality of rows spaced apart from each other by removing the exposed silicon oxide layer 200 and removing the photoresist layer remaining on the silicon oxide layer 200 through a photolithography process and an etching process. The silicon oxide layer 200 is manufactured.

Referring to FIG. 6, a first gallium nitride (GaN) layer 201a is grown from a sapphire substrate 100 exposed between rows of the plurality of silicon oxide layers 200, wherein the first GaN layer 201a is grown. Is epitaxial lateral overgrowth. According to the above method, GaN crystals grow in the horizontal direction, whereby a triangular first GaN layer 201a is formed between the oxide layers 200 as shown in FIG. 6.

Referring to FIG. 7, a second GaN layer 201 is again stacked on the horizontal overgrown first GaN layer 201a.

Referring to FIG. 8, an n-gallium nitride (GaN) layer 202 doped with n-type impurities on the GaN layer 201, a light emitting layer (Multi-Quantum Well, 203), and p- doped with p-type impurities Gallium nitride (GaN) layers 204 are sequentially stacked.

Referring to FIG. 9, the photoresist layer 302 and the mask layer 303 are sequentially stacked on the p-GaN layer 204, and the mask layer 303 is patterned.

Referring to FIG. 10, the photoresist layer 302 exposed between the mask layers 303 is etched to expose the p-GaN layer 204.

Referring to FIG. 11, the light emitting layer 203 under the exposed p-GaN layer 204 is also etched by a reactive ion etching process, so that the n-GaN region 205, that is, the n-GaN layer 201 to the outside. Define this exposed area.

Referring to FIG. 12, metal contacts 206 are deposited on the n-GaN region 205 and the p-GaN layer 204, respectively. In one embodiment of the present invention, the metal contact 206 is a gold / chromium alloy, and forms an ohmic contact with the device layer through a rapid thermal annealing (RTA) process at 600 ° C. for 1 minute after lamination.

Referring to FIG. 13, a second metal layer 207 for supporting GaN is stacked on the entire surface of the substrate of FIG. 12, and the second metal layer is also a gold / chromium alloy similarly to the metal contact, but the scope of the present invention is not limited thereto. Do not.

Referring to FIG. 14, a photoresist layer 304 is stacked on the second metal layer 207, and a patterned mask layer 305 is formed again. In this case, the mask layer 305 covers all of the regions where the metal contacts are formed, thereby manufacturing GaN LED devices having the same shape and size as the mask layer 305.

Referring to FIG. 15, all photoresist layers 304 except for the photoresist layer 304 in the region where the mask layer 305 is formed are removed through the photolithography process.

Referring to FIG. 16, all device layers except the device layer under the photoresist layer 304 remaining through the RIE etching process are removed. As a result, a plurality of GaNLED unit devices are formed on the sapphire substrate 100.

Referring to FIG. 17, the silicon oxide layer 200 remaining on the sapphire substrate 100 is removed using the HF. That is, the present invention removes the GaN LED unit device from the sacrificial substrate by a chemical lift-off method, wherein a sacrificial layer (which is a silicon oxide layer in one embodiment of the present invention) is provided between the substrate and the device to react with a specific chemical. . In this chemical lift-off method, the GaN unit device having weakened binding force with the sapphire substrate 100 is effectively separated from the sacrificial substrate by the transfer substrate 210 as shown in FIG. 18.

Referring to FIG. 18, a transfer substrate 210 such as PDMS is in contact with a GaN unit device device from which the silicon oxide layer 200 has been removed, and more specifically, the second metal layer 207 of the device.

Referring to FIG. 19, a GaNLED unit device is separated from a sapphire substrate 100 as a sacrificial substrate through the transfer substrate 210.

20 to 22, the GaN LED device separated from the sapphire substrate 100 through FIG. 19 is transferred to the plastic substrate 500 having the adhesive layer 501 laminated using the transfer substrate 210. The PDMS transfer substrate 210 is removed.

Referring to FIG. 23, the second metal layer 207 used to induce a sufficient contact area with the transfer substrate as PDMS is removed.

Referring to FIG. 24, a first transparent insulating layer (epoxy) 310 is coated on the plastic substrate 500 for electrical passivation of a device, and a mask layer 306 for exposing the first metal layer of the device to the outside. ) Is formed. In one embodiment of the present invention, the first transparent insulating layer 310 may be a polymer material such as SU8, polyimide, polyurethane, etc., but the scope of the present invention is not limited thereto.

Referring to FIG. 25, the first transparent insulating layer 310 is opened through a photolithography process using the mask layer 306 to form a first metal layer 206 formed on the p-GaN layer and the n-GaN layer, respectively. ) Is exposed to the outside.

Referring to FIG. 26, a first metal line 502 is formed on a metal contact (n-GaN metal contact 206) formed on an n-GaN layer having a lower height. In one embodiment of the present invention, the first metal line 502 is configured such that one or more GaN LED unit devices electrically connect n-GaN metal contacts.

Referring to FIG. 27, a second transparent insulating layer 320 is stacked on the substrate, and a mask layer 307 for connecting to an ohmic contact of p-GaN is again formed on the second transparent insulating layer 320. Is formed.

28 and 29, a metal contact 206 formed on a p-GaN layer having a high height is exposed by a photolithographic process using a mask layer 307, and then the metal contact 206 is electrically The second metal line 503 is formed to be connected to. In this case, an end portion of the first metal line 502 having a low height is exposed between the second transparent insulating layers. In one embodiment of the present invention, the first metal line and the second metal line have different heights, and the connection directions of the unit elements are different from each other. That is, if the first metal line connecting the n-GaN contact is in the longitudinal direction, the second metal line is in the column direction. As a result, an array-type flexible light source including a plurality of GaN LED unit elements in a row is realized.

The present invention provides an optoelectric photonic device using a plurality of GaN LED unit devices having the flexibility. This will be described in detail below.

30 to 32 are views illustrating a method of manufacturing an optoelectric optical device according to an embodiment of the present invention.

Referring to FIG. 30, a third transparent insulating layer 330 is stacked on a second transparent insulating layer 320 of the plurality of GaN LED unit devices disclosed in FIG. 29 to form a microelectrode array (MEA). A fine pattern 601 is formed on the third transparent insulating layer. In addition, the third transparent insulation layer 330 is patterned so that an end portion (first metal line pad 502) to which the first metal line is connected and an end portion (second metal line pad 503) to which the second metal line is connected to the outside are formed. Exposed.

Referring to FIG. 31, although not all of the third transparent insulating layer 330 itself is etched, the microelectrode array pattern 601 which etched the third transparent insulating layer 330 to a predetermined depth is stacked and patterned with a metal layer. MEA electrode line 602 is formed. In addition, an electrode pad 602a having a wider width than the line is connected to an end of the MEA electrode line.

Referring to FIG. 32, a fourth transparent insulating layer 340, which is the last insulating layer, is stacked on the third transparent insulating layer 330, and then the MEA electrode line, the pads 602 and 602a, and the GaN LED line are stacked. The fourth transparent insulating layer 340 is patterned to expose portions of the first and second metal line ends 502 and 503 connected thereto. As a result, an array type electrode based on the first and second metal lines is formed in each unit GaN LED device, and also for electrically detecting neuronal changes in response to light generated independently in each unit GaN LED device. A microelectrode array is formed.

The flexible gallium nitride light emitting diode (GaN LED) device according to the present invention manufactured according to the above-described method may be inserted into a human body having a curved structure instead of a flat surface to irradiate light. In particular, the corrugated cerebral cortex located directly below the spherical skull or cranial bones plays a role in cognition, thinking, language, and memory, and Parkinson's disease is particularly related to symptoms caused by neurons located on the surface. The GaN LED device is easily surface-stimulated as described above, and can be implanted in a narrow position between the left and right brains. In addition, the GaN LED device according to the present invention is composed of a plurality of unit devices, each form an LED array that is independently turned on / off. Therefore, light on-off stimulation of nerve cells is possible at various sites, thus facilitating identification of neural circuits. In addition, the flexible photoelectric device for photogenetics according to the present invention is partially exposed to the surface of the insulating layer MEA electrode line, by detecting the action potential of the nerve cells reacted by the light generated from the GaN LED device from the MEA electrode, feedback back can do.

The GaN LED array device according to the present invention is very useful in light genetics, light implantability, and size can be used in a narrow space in photoelectricity. For example, nerve cells that emerge like branches between vertebral bones can be more easily damaged if they are structurally disc-shaped, injured by trauma, or bent spine bones. . Scars of spinal nerve cells (damage) are associated with various physical symptoms (digestive organs, heart, blood vessels, bladder, sweat glands, etc.). However, since the shape of the spine is not flat and bent, the rigid LED is not available, and thus the flexible LED device according to the present invention is advantageously used. In particular, the optogenetic system according to the present invention, which is capable of supplying power in vivo, is useful for spinal injury patients who are inconvenient to move.

FIG. 33 is a schematic diagram illustrating a pattern stimulus using the flexible LED arrays 800a and 800b according to an embodiment of the present invention, and a method of reading the same into a MEA 800c.

Referring to FIG. 33, the unit GaN LED device is turned on (800b) or turned off (800c). The MEA, which is configured to be 1: 1 matched to each unit device, electrically measures the change of nerve cells due to the generated light of each unit device.

34 is a view for explaining an example of the use of the photoelectric device for photoelectrics according to the present invention.

Referring to FIG. 34, as shown in FIG. 33, the GaN LED device of the photoelectric device according to the present invention is turned on and off, and thus a change in action potential of the neuron is measured (900). Thereafter, the measured change value is transmitted to the outside (901). Thereafter, the GaN LED elements of the photoelectric device for photoelectricity inserted into the human body according to the external input signal are turned on and off again for each unit device.

Claims (15)

Method for manufacturing a flexible gallium nitride light emitting diode device, the method
Manufacturing a gallium nitride light emitting diode device on the sacrificial substrate;
Chemically separating the gallium nitride light emitting diode device from the sacrificial substrate, wherein the chemical separation is performed by chemically removing the sacrificial layer between the sacrificial substrate and the gallium nitride light emitting diode device. Flexible gallium nitride light emitting diode device manufacturing method. The method of claim 1,
Depositing a silicon oxide layer on the sacrificial substrate;
Patterning the stacked silicon oxide layers and forming a plurality of spaced apart silicon oxide layer rows;
Growing a first gallium nitride layer in a space between the plurality of silicon oxide layers;
Stacking a second gallium nitride layer on the silicon oxide layer and the first gallium nitride layer;
Forming a gallium nitride device layer including n-gallium nitride layers / light emitting layers / p-gallium nitride layers sequentially stacked on the stacked second gallium nitride layers;
Patterning the formed gallium nitride device layer to form a plurality of unit gallium nitride light emitting diode devices; And
And removing the silicon oxide layer on the sacrificial substrate, and transferring the formed unitary gallium nitride light emitting diode elements to a plastic substrate. The method of claim 2,
Removing the silicon oxide layer is a method of manufacturing a flexible gallium nitride light emitting diode device, characterized in that the chemical process. The method of claim 2,
The gallium nitride light emitting diode device is a flexible gallium nitride light emitting diode device manufacturing method, characterized in that the structure of a plurality of unit light emitting diode devices forming an array. The method of claim 2, wherein the method
After the gallium nitride device layer deposition step, exposing the n-gallium nitride layer and the p-gallium nitride layer to the outside;
Forming a metal contact on each of the n-gallium nitride layer and the p-gallium nitride layer;
And forming a first metal line connecting the metal contact on the n-gallium nitride layer and a second metal line connecting the metal contact on the p-gallium nitride layer. Device manufacturing method. The method of claim 2,
The growth of the first gallium nitride layer is a method of manufacturing a flexible gallium nitride light emitting diode device, characterized in that the epitaxial horizontal overgrowth. A flexible gallium nitride light emitting diode device, the device comprising
A plastic substrate;
A gallium nitride light emitting diode unit device provided on the substrate and including a n-gallium nitride layer / light emitting layer / p-gallium nitride layer sequentially stacked;
A metal contact stacked on an n-gallium nitride layer and a p-gallium nitride layer of the gallium nitride light emitting diode unit device;
A first metal line and a second metal line connecting the metal contacts stacked on the n-gallium nitride layer and the p-gallium nitride layer of the gallium nitride light emitting diode unit device, respectively; And
A flexible gallium nitride light emitting diode device comprising a transparent insulating layer laminated on the first metal line and the second metal line. 8. The method of claim 7,
An end portion of the first metal line and the second metal line is exposed between the transparent insulating layer, the flexible gallium nitride light emitting diode device. The method of claim 8,
A flexible gallium nitride light emitting diode device, characterized in that a transparent insulating layer is provided between the first metal line and the second metal line. The method of claim 9,
And the first metal line and the second metal line connect gallium nitride light emitting diode unit devices of different species and columns. An optical device for optogenetics comprising a flexible gallium nitride light emitting diode device according to any one of claims 7 to 10, wherein the optical device
A photoelectric device for photoelectricity, comprising: a microelectrode array comprising a plurality of electrode lines stacked on a transparent insulating layer on a flexible gallium nitride light emitting diode device. 12. The method of claim 11,
The microelectrode array is photoelectric device optical element, characterized in that provided to correspond to each unit flexible gallium nitride light emitting diode device. 13. The method of claim 12,
The microelectrode array is a photoelectric device for photoelectricity, characterized in that for detecting the action potential change of the nerve cells reacted by the light generated by the gallium nitride light emitting diode device. A neuronal cell analysis method comprising electrically measuring neuronal changes by using the microelectrode array of the photoelectric genetic device of claim 13 implanted in a living body. Stimulating a living body by generating light from the gallium nitride light emitting diode device of the photoelectric device according to claim 13 implanted in a living body; And
The optical stimulation method using the photoelectric device for photoelectrics, characterized in that for measuring the action potential change of the nerve cells in response to the generated light with the microelectrode array.

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