CN111430513A - Preparation method of nano-column and preparation method of nano-column L ED device - Google Patents

Abstract

Embodiments of the present invention provide a method for preparing a nano-column and a method for preparing a nano-column LED device. The preparation method of the nano-pillar includes: evaporating a first thin film on the upper surface of an LED wafer, wherein the LED wafer includes a p-type GaN layer, a quantum well active layer, an n-type GaN layer and a substrate; The thin-film LED wafer is thermally annealed to make the first thin film form ohmic contact with the p-type GaN layer; a second thin film is deposited on the upper surface of the first thin film, and the lower surface of the second thin film is in contact with the first thin film; A plurality of auxiliary nano-patterns are prepared on the upper surface of the film; the second film is etched through the auxiliary nano-pattern to form a plurality of masks; the first film, the p-type GaN layer, the quantum well active layer and the n-type film are etched through the mask. The GaN layer is etched to form a plurality of LED nano-pillars, and both ends of the LED nano-pillars are used to connect with electrodes. The effect of improving the P-type ohmic contact performance of the nano-LED is achieved.

Description

Preparation method of nano-column and preparation method of nano-column LED device

technical field

Embodiments of the present invention relate to the technical field of micro-nano device manufacturing, and in particular, to a method for preparing nano-pillars and a method for preparing nano-pillar LED devices.

Background technique

Low-dimensional semiconductor devices have different optical and electrical properties from bulk materials, and have attracted much attention from academia and industry in recent years. Typical examples are two-dimensional quantum wells, one-dimensional nanopillars, and zero-dimensional quantum dots. Taking the gallium nitride-based (GaN) nanoscale LED device as an example, because of its strong quantum confinement along the quantum well growth direction and the direction parallel to the quantum well, the quantum dot-like characteristics of the luminescent core InGaN well layer make it have strong quantum confinement. Unique optoelectronic properties. When the size of the device is reduced to the nanometer level, the stress on the quantum well is basically released, and the quantum confinement Stark effect (QCSE) is eliminated. In addition, due to the quantum dot-like characteristics of nanoscale LEDs and the strong exciton binding energy of GaN, GaN-based nanoscale LEDs can also be used as single-photon light sources for quantum computing, quantum communication and other fields.

Currently, conventional methods for preparing nanopillars include: electron beam exposure (EBL) or focused ion beam etching (FIB). Taking electron beam exposure (EBL) as an example, electron beam exposure uses the shorter de Broglie wavelength of the electron beam to expose and develop the sample, and further evaporate the electrode metal.

However, although the EBL process has high precision, it also limits the thickness of the electrode metal, thus weakening its conductivity to a certain extent, resulting in poor P-type ohmic contact performance of nano-LEDs.

SUMMARY OF THE INVENTION

The embodiments of the present invention provide a method for preparing a nano-pillar and a method for preparing a nano-pillar LED device, so as to achieve the effect of improving the P-type ohmic contact performance of the nano-LED.

In a first aspect, an embodiment of the present invention provides a method for preparing a nanopillar, including:

A first thin film is evaporated on the upper surface of an LED wafer, wherein the LED wafer includes a p-type GaN layer, a quantum well active layer, an n-type GaN layer and a substrate, wherein the upper surface of the p-type GaN layer serves as the LED The upper surface of the wafer, the lower surface of the p-type GaN layer is in contact with the upper surface of the quantum well active layer, the lower surface of the quantum well active layer is in contact with the upper surface of the n-type GaN layer, the lower surface of the n-type GaN layer and the lining The top surface of the bottom is in contact;

thermally annealing the LED wafer on which the first thin film is evaporated, so that the first thin film forms an ohmic contact with the p-type GaN layer;

depositing a second film on the upper surface of the first film, and the lower surface of the second film is in contact with the first film;

preparing a plurality of auxiliary nano-patterns on the upper surface of the second film;

etching the second thin film through the auxiliary nanopattern to form a plurality of masks;

The first thin film, the p-type GaN layer, the quantum well active layer and the n-type GaN layer are etched through the mask to form a plurality of LED nano-pillars, and both ends of the LED nano-pillars are used for connecting with electrodes .

Optionally, the etching of the second thin film through the auxiliary nano-pattern to form a plurality of masks includes:

spraying the first etching gas along a first target direction, where the first target direction is a direction perpendicular to the upper surface of the second thin film, and the auxiliary nano-pattern is used to block the first etching gas;

The second thin film forms a plurality of masks under the etching of the first etching gas.

Optionally, the first etching gas is CHF ₃ or O ₂ .

Optionally, the etching of the first thin film, the p-type GaN layer, the quantum well active layer and the n-type GaN layer through the mask to form a plurality of LED nano-pillars includes:

spraying a second etching gas along a second target direction, where the second target direction is a direction perpendicular to the upper surface of the first thin film, and the mask is used to block the second etching gas;

The first thin film, the p-type GaN layer, the quantum well active layer and the n-type GaN layer are etched by the second etching gas to form a plurality of intermediate nano-columns;

The mask of the middle nanopillars is removed to form a plurality of LED nanopillars.

Optionally, the second etching gas is Cl ₂ or Cl ₃ B.

Optionally, removing the mask of the middle nano-pillars to form a plurality of LED nano-pillars includes:

The mask is removed by hydrofluoric acid to form a plurality of LED nanopillars.

Optionally, the first film is a silicon oxide film.

Optionally, the second film is an ITO film.

Optionally, the temperature of the thermal annealing treatment is 650°C-850°C, and the annealing time is 0.5 minutes-10 minutes.

In a second aspect, an embodiment of the present invention provides a method for preparing a nano-pillar LED device, including:

A first thin film is evaporated on the upper surface of an LED wafer, wherein the LED wafer includes a p-type GaN layer, a quantum well active layer, an n-type GaN layer and a substrate, wherein the upper surface of the p-type GaN layer serves as the LED The upper surface of the wafer, the lower surface of the p-type GaN layer is in contact with the upper surface of the quantum well active layer, the lower surface of the quantum well active layer is in contact with the upper surface of the n-type GaN layer, the lower surface of the n-type GaN layer and the lining The top surface of the bottom is in contact;

thermally annealing the LED wafer on which the first thin film is evaporated, so that the first thin film forms an ohmic contact with the p-type GaN layer;

depositing a second film on the upper surface of the first film, and the lower surface of the second film is in contact with the first film;

preparing a plurality of auxiliary nano-patterns on the upper surface of the second film;

etching the second thin film through the auxiliary nanopattern to form a plurality of masks;

The first thin film, the p-type GaN layer, the quantum well active layer and the n-type GaN layer are etched through the mask to form a plurality of LED nano-pillars, and both ends of the LED nano-pillars are used for connecting with electrodes ;

A first electrode is prepared at one end of the LED nanocolumn carrying the first thin film, and a second electrode is prepared at one end of the n-type GaN layer of the LED nanocolumn to form a nanocolumn LED device, wherein the quantum well The active layer is not in contact with the first and second electrodes.

In the embodiment of the present invention, the first thin film is evaporated on the upper surface of the LED wafer, wherein the LED wafer includes a p-type GaN layer, a quantum well active layer, an n-type GaN layer and a substrate, wherein the upper surface of the p-type GaN layer is The surface is used as the upper surface of the LED wafer, the lower surface of the p-type GaN layer is in contact with the upper surface of the quantum well active layer, the lower surface of the quantum well active layer is in contact with the upper surface of the n-type GaN layer, and the n-type GaN layer The lower surface of the substrate is in contact with the upper surface of the substrate; thermal annealing is performed on the LED wafer on which the first thin film is evaporated, so that the first thin film and the p-type GaN layer form ohmic contact; A second film is deposited on the upper surface of a film, and the lower surface of the second film is in contact with the first film; a plurality of auxiliary nano-patterns are prepared on the upper surface of the second film; The second thin film is etched to form a plurality of masks; the first thin film, the p-type GaN layer, the quantum well active layer and the n-type GaN layer are etched through the masks to form a plurality of LED nano-pillars , the two ends of the LED nano-columns are used to connect with the electrodes, which solves the limitation of the thickness of the electrode metal by the commonly used preparation methods, so its conductivity is weakened to a certain extent, resulting in poor P-type ohmic contact performance of the nano-LED The effect of improving the P-type ohmic contact performance of the nano-LED is realized.

Description of drawings

Fig. 1 is the schematic flow sheet of the preparation method of a kind of nano-pillar provided in the embodiment of the present invention;

FIG. 2 is a schematic diagram of evaporating a first thin film on an upper surface of an LED wafer according to Embodiment 1 of the present invention;

3 is a schematic diagram of depositing a second film on the upper surface of the first film according to Embodiment 1 of the present invention;

4 is a schematic diagram of preparing a plurality of auxiliary nano-patterns on the upper surface of the second film according to Embodiment 1 of the present invention;

5 is a schematic diagram of etching a second thin film to form a plurality of masks according to Embodiment 1 of the present invention;

6 is a schematic structural diagram of an intermediate nanocolumn provided in Embodiment 1 of the present invention;

FIG. 7 is a schematic structural diagram of an LED nanocolumn according to Embodiment 1 of the present invention;

8 is a schematic flowchart of a method for preparing a nano-pillar LED device according to Embodiment 2 of the present invention;

FIG. 9 is a schematic structural diagram of a nano-pillar LED device according to Embodiment 2 of the present invention.

Detailed ways

The present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention, but not to limit the present invention. In addition, it should be noted that, for the convenience of description, the drawings only show some but not all structures related to the present invention.

Before discussing the exemplary embodiments in greater detail, it should be mentioned that some exemplary embodiments are described as processes or methods depicted as flowcharts. Although the flowchart depicts the steps as a sequential process, many of the steps may be performed in parallel, concurrently, or concurrently. Furthermore, the order of the steps can be rearranged. The process may be terminated when its operation is complete, but may also have additional steps not included in the figures. A process may correspond to a method, function, procedure, subroutine, subcomputer program, or the like.

Furthermore, the terms "first," "second," etc. may be used herein to describe various directions, acts, steps or elements, etc., but are not limited by these terms. These terms are only used to distinguish a first direction, act, step or element from another direction, act, step or element. For example, a first film may be referred to as a second film, and similarly, a second film may be referred to as a first film, without departing from the scope of this application. Both the first film and the second film are films, but they are not the same film. The terms "first", "second" and the like should not be understood as indicating or implying relative importance or implying the number of technical features indicated. Thus, a feature defined as "first" or "second" may expressly or implicitly include one or more of that feature. In the description of the present invention, "plurality" means at least two, such as two, three, etc., unless otherwise expressly and specifically defined.

Example 1

FIG. 1 is a schematic flowchart of a method for preparing a nano-column according to Embodiment 1 of the present invention, which can be applied to the scene of preparing an LED nano-column.

As shown in FIG. 1 , the preparation method of the nanocolumn provided in the first embodiment of the present invention includes:

S110. Evaporate a first thin film on the upper surface of the LED wafer, wherein the LED wafer includes a p-type GaN layer, a quantum well active layer, an n-type GaN layer and a substrate, wherein the upper surface of the p-type GaN layer serves as the The upper surface of the LED wafer, the lower surface of the p-type GaN layer is in contact with the upper surface of the quantum well active layer, the lower surface of the quantum well active layer is in contact with the upper surface of the n-type GaN layer, and the lower surface of the n-type GaN layer in contact with the upper surface of the substrate.

The LED chip may be a GaN-based blue LED chip or a GaN-based green LED chip. The LED chip in this embodiment is not specifically limited, and can be selected according to needs. Wherein, the LED wafer includes a p-type GaN layer, a quantum well active layer, an n-type GaN layer and a substrate, wherein the upper surface of the p-type GaN layer serves as the upper surface of the LED wafer, and the lower surface of the p-type GaN layer is connected to the quantum well. The upper surface of the source layer is in contact, the lower surface of the quantum well active layer is in contact with the upper surface of the n-type GaN layer, and the lower surface of the n-type GaN layer is in contact with the upper surface of the substrate. Optionally, the quantum well active layer may be an _{InxGa1XN quantum} well active layer or a GaN quantum well active layer, which is not specifically limited in this embodiment. The substrate may be a smooth substrate made of sapphire material, which is not specifically limited in this embodiment.

Optionally, the first film may be a conductive transparent material, such as an ITO (IndiumTinOxide) film, etc., which is not limited here. Specifically, a 100-200 nm ITO film can be deposited on the upper surface of the LED wafer by magnetron sputtering or electron beam evaporation. Optionally, the first film can be a single layer or a multi-layer, which can be set as required.

Referring to FIG. 2 , FIG. 2 is a schematic diagram of evaporating a first thin film on the upper surface of the LED wafer provided by this embodiment. As can be seen from FIG. 2 , the LED wafer 300 includes a p-type GaN layer 301 , a quantum well active layer 302 , an n-type GaN layer 303 and a substrate 304 , wherein the upper surface of the p-type GaN layer 301 serves as the upper surface of the LED wafer 300 , the lower surface of the p-type GaN layer 301 is in contact with the upper surface of the quantum well active layer 302, the lower surface of the quantum well active layer 302 is in contact with the upper surface of the n-type GaN layer 303, and the lower surface of the n-type GaN layer 303 and The upper surface of the substrate 304 is in contact, and the first thin film 200 is in contact with the upper surface of the LED wafer 300 .

S120 , thermally annealing the LED wafer on which the first thin film is evaporated, so that the first thin film and the p-type GaN layer form an ohmic contact.

In this step, after thermal annealing of the vapor-deposited first thin film, the first thin film can already form a good ohmic contact with the P-type GaN layer of the LED wafer. Optionally, the temperature of the thermal annealing treatment is 650°C-850°C, and the annealing time is 0.5 minutes-10 minutes. The temperature and time of the thermal annealing treatment can be selected as required, which is not specifically limited in this embodiment. Preferably, the process parameters of the thermal annealing treatment are: the temperature is 800° C., and the annealing time is 0.5 minutes.

In an optional embodiment, thermally annealing the LED wafer on which the first thin film is evaporated includes:

placing the LED wafer on which the first thin film is evaporated in a closed space with a preset ratio of nitrogen and oxygen; thermally annealing the LED chip on which the first thin film is evaporated in the closed space deal with.

In this embodiment, the LED wafer on which the first thin film is evaporated is placed in a closed space with a preset ratio of nitrogen and oxygen for thermal annealing. Optionally, the preset ratio may be 4:1, and the preset ratio may be set as required, so as to achieve the best annealing effect, which is not specifically limited in this embodiment.

S130 , depositing a second thin film on the upper surface of the first thin film, and the lower surface of the second thin film is in contact with the first thin film.

Wherein, the second film may be an insulating film, such as silicon monoxide or silicon dioxide, which is not specifically limited here. Optionally, the second film may be a single layer or a multi-layer, which is not specifically limited here. Specifically, plasma enhanced chemical vapor deposition (PECVD) may be used to deposit the second thin film on the first thin film. Referring to FIG. 3 , FIG. 3 is a schematic diagram of depositing a second thin film on the upper surface of the first thin film according to the present embodiment. It can be seen from FIG. 3 that the second film 100 is deposited on the upper surface of the first film 200 , and the upper surface of the first film 200 is in contact with the lower surface of the second film 100 .

S140, preparing a plurality of auxiliary nano-patterns on the upper surface of the second thin film.

Wherein, the auxiliary nano-pattern refers to the nano-pattern used for auxiliary etching of the second thin film. Specifically, an auxiliary nano-pattern can be prepared on the upper surface of the second thin film by using a nano-imprinting process. Referring to FIG. 4 , FIG. 4 is a schematic diagram of preparing a plurality of auxiliary nano-patterns on the upper surface of the second thin film according to the present embodiment. It can be seen from FIG. 4 that a plurality of auxiliary nano-patterns 400 are prepared on the upper surface of the second thin film 100 .

S150 , etching the second thin film through the auxiliary nano-pattern to form a plurality of masks.

The mask is used to assist in etching the first thin film, the p-type GaN layer, the quantum well active layer and the n-type GaN layer. The mask may include the auxiliary nano-pattern and the second thin film; or may only include the second thin film. Specifically, when the mask includes the auxiliary nano-pattern and the second thin film, after etching the second thin film, the auxiliary nano-pattern and the second thin film are used as the mask; when the mask includes the second thin film, the auxiliary nano-pattern and the second thin film can be used as the mask first; The embossing glue of the nano-pattern is removed, and the second thin film remains, and the second thin film is used as a mask.

In an optional embodiment, the second thin film is etched through the auxiliary nanopattern to form a plurality of masks, including:

The first etching gas is sprayed along a first target direction, the first target direction is a direction perpendicular to the upper surface of the second thin film, and the auxiliary nano-pattern is used to block the first etching gas; so The second thin film forms a plurality of masks under the etching of the first etching gas.

Among them, the first etching gas is used to etch the second thin film, but the gas that cannot etch the auxiliary nano-pattern and the p-type GaN layer of the LED wafer can be selected according to needs. etch to form a mask. Optionally, the first etching gas includes but is not limited to CHF ₃ or O ₂ .

Referring to FIG. 5 , FIG. 5 is a schematic diagram of etching the second thin film to form a plurality of masks provided by this embodiment. It can be seen from FIG. 5 that a plurality of masks 500 are formed after etching the second thin film.

S160. Etch the first thin film, the p-type GaN layer, the quantum well active layer and the n-type GaN layer through the mask to form a plurality of LED nano-columns, and two ends of the LED nano-columns are used for connecting with the LED nano-columns. electrode connection.

In this step, the LED nanocolumns include a first thin film, a p-type GaN layer, a quantum well active layer and an n-type GaN layer.

In an optional embodiment, the first thin film, the p-type GaN layer, the quantum well active layer and the n-type GaN layer are etched through the mask to form a plurality of LED nanopillars, including:

spraying a second etching gas along a second target direction, the second target direction being a direction perpendicular to the upper surface of the first thin film, and the mask is used to block the second etching gas; the The first thin film, the p-type GaN layer, the quantum well active layer and the n-type GaN layer are etched by the second etching gas to form a plurality of middle nanopillars; the mask of the middle nanopillars is removed to form a plurality of middle nanopillars. LED nanopillars.

Among them, the second etching gas refers to the gas used for etching the first thin film, p-type GaN layer, quantum well active layer and n-type GaN layer, but the gas that cannot etch the mask and the substrate can be used as required. to make a selection. Optionally, the second etching gas includes but is not limited to Cl ₂ or Cl ₃ B. The middle nanopillar refers to the result obtained by etching the first thin film, the p-type GaN layer, the quantum well active layer and the n-type GaN layer through a mask. Wherein, the middle nano-column includes a mask, a first thin film, a p-type GaN layer, a quantum well active layer and an n-type GaN layer. The LED nanopillars can be obtained after removing the mask of the middle nanopillars. Optionally, the mask may be removed by hydrofluoric acid to form a plurality of LED nanopillars. Specifically, the middle nano-columns can be easily soaked with hydrofluoric acid to form LED nano-columns.

Referring to FIG. 6 , FIG. 6 is a schematic structural diagram of an intermediate nanocolumn provided in this embodiment. It can be seen from FIG. 6 that the middle nanocolumn 50 includes a mask 500 , a first thin film 200 , a p-type GaN layer 301 , a quantum well active layer 302 and an n-type GaN layer 303 .

Referring to FIG. 7 , FIG. 7 is a schematic structural diagram of an LED nanocolumn provided in this embodiment. As can be seen from FIG. 7 , the LED nanocolumns 40 include a first thin film 200 , a p-type GaN layer 301 , a quantum well active layer 302 and an n-type GaN layer 303 . Wherein, the first thin film 200 has formed a good ohmic contact with the p-type GaN layer 301 .

The technical solution of the embodiment of the present invention is to evaporate a first thin film on the upper surface of an LED wafer, wherein the LED wafer includes a p-type GaN layer, a quantum well active layer, an n-type GaN layer and a substrate, wherein the p-type GaN layer The upper surface of the GaN layer is used as the upper surface of the LED wafer, the lower surface of the p-type GaN layer is in contact with the upper surface of the quantum well active layer, and the lower surface of the quantum well active layer is in contact with the upper surface of the n-type GaN layer, The lower surface of the n-type GaN layer is in contact with the upper surface of the substrate; thermal annealing is performed on the LED wafer on which the first thin film is evaporated, so that the first thin film forms an ohmic contact with the p-type GaN layer; A second film is deposited on the upper surface of the first film, and the lower surface of the second film is in contact with the first film; a plurality of auxiliary nano-patterns are prepared on the upper surface of the second film; The nanopattern etches the second thin film to form a plurality of masks; the first thin film, the p-type GaN layer, the quantum well active layer and the n-type GaN layer are etched through the masks to form a plurality of masks; LED nano-columns, the two ends of the LED nano-columns are used to connect with electrodes, since the first thin film has conductivity, and the first thin film has formed a good ohmic contact with the p-type GaN layer, thereby improving the p-type GaN layer. The area of ohmic contact with the electrode achieves the technical effect of improving the P-type ohmic contact performance of the nano-LED.

Embodiment 2

FIG. 8 is a schematic flowchart of a method for preparing a nano-pillar LED device according to Embodiment 2 of the present invention, and this embodiment can be applied to a scenario of preparing a nano-pillar LED device.

As shown in FIG. 8 , the preparation method of the nano-pillar LED device provided in this embodiment may include, wherein:

S210. Evaporate a first thin film on the upper surface of the LED wafer, wherein the LED wafer includes a p-type GaN layer, a quantum well active layer, an n-type GaN layer and a substrate, wherein the upper surface of the p-type GaN layer serves as the The upper surface of the LED wafer, the lower surface of the p-type GaN layer is in contact with the upper surface of the quantum well active layer, the lower surface of the quantum well active layer is in contact with the upper surface of the n-type GaN layer, and the lower surface of the n-type GaN layer in contact with the upper surface of the substrate.

S220, thermally annealing the LED wafer on which the first thin film is evaporated, so that the first thin film and the p-type GaN layer form an ohmic contact.

S230 , depositing a second thin film on the upper surface of the first thin film, and the lower surface of the second thin film is in contact with the first thin film.

S240 , preparing a plurality of auxiliary nano-patterns on the upper surface of the second thin film.

S250 , etching the second thin film through the auxiliary nano-pattern to form a plurality of masks.

S260, etching the first thin film, the p-type GaN layer, the quantum well active layer, and the n-type GaN layer through the mask to form a plurality of LED nano-columns, and two ends of the LED nano-columns are used for connecting with the LED nano-columns. electrode connection.

S270, preparing a first electrode at one end of the LED nano-column carrying the first thin film, and preparing a second electrode at one end of the n-type GaN layer of the LED nano-column, so as to form a nano-column LED device, wherein the The quantum well active layer is not in contact with the first and second electrodes.

In this step, a first electrode is prepared at one end of the LED nanocolumn carrying the first thin film, and a second electrode is prepared at one end of the n-type GaN layer of the LED nanocolumn. Specifically, this embodiment does not specifically limit how to prepare electrodes at both ends of the LED nanocolumns.

In an optional embodiment, preparing a first electrode at one end of the LED nanocolumn carrying the first thin film, and preparing a second electrode at one end of the n-type GaN layer of the LED nanocolumn may include:

The substrate and connected multiple LED nanopillars are placed as a sample in a solution (such as alcohol or isopropanol) for sonication in alcohol or isopropanol, and the energy of the ultrasound is used to transfer the LED nanopillars into the solution , forming a suspension carrying the LED nanocolumns, and then using a burette or a pipette to drop the suspension on an insulating substrate, and heating the insulating substrate to evaporate the solution, leaving the dried LED nanocolumns. The insulating substrate on which the LED nanocolumns are placed is placed in a focused ion beam (FIB) device or an electron beam exposure (EBL) device, so that a first electrode is prepared at the end of the LED nanocolumn that carries the first film, and the LED nanocolumn is A second electrode was prepared at one end of the n-type GaN layer of the pillar, thereby forming a nanopillar LED device.

Specifically, a scanning electron microscope in a focused ion beam (FIB) device or an electron beam exposure (EBL) device finds both ends of the LED nanocolumn, and then grabs the first electrode and places it on the LED nanocolumn carrying the first thin film. At one end, grab the second electrode and place it on one end of the n-type GaN layer of the LED nanopillar, and then bombard the area of the first electrode wrapped with the end of the first film by a focused ion beam or electron beam, and wrap the second electrode The region with one end of the n-type GaN layer is bombarded, thereby obtaining a nanopillar LED device. Optionally, the material of the first electrode and the second electrode may be metal, such as platinum (pt), and other materials may be selected as required, which is not specifically limited here. Specifically, due to the small size of the nano-pillar LED device, when measuring the positive electrode (p-pole) and negative electrode (n-pole) of the nano-pillar LED device, one pole of the nano-pillar LED device can be placed on a large area (for example, The other pole of the nano-pillar LED device is placed on another large-area electrical conductor, and the two electrical conductors are measured by a probe to determine the positive and negative electrodes of the nano-pillar LED device.

Referring to FIG. 9 , FIG. 9 is a schematic structural diagram of a nano-pillar LED device provided in this embodiment. As can be seen from FIG. 9 , the nano-column LED device includes a first electrode 10 , a second electrode 20 and an LED nano-column 40 , wherein the first electrode 10 is prepared at the end of the LED nano-column 40 that carries the first thin film 200 , and the second electrode 20 It is prepared at one end of the n-type GaN layer 303 of the LED nanocolumn 40 , and the quantum well active layer 302 is not in contact with the first electrode 10 and the second electrode 20 . Wherein, the first thin film 200 may be in contact with the first electrode 10 alone, or the first thin film 200 and the p-type GaN layer 301 may be in contact with the first electrode 10 at the same time.

The technical solution of the embodiment of the present invention is to evaporate a first thin film on the upper surface of an LED wafer, wherein the LED wafer includes a p-type GaN layer, a quantum well active layer, an n-type GaN layer and a substrate, wherein the p-type GaN layer The upper surface of the GaN layer is used as the upper surface of the LED wafer, the lower surface of the p-type GaN layer is in contact with the upper surface of the quantum well active layer, and the lower surface of the quantum well active layer is in contact with the upper surface of the n-type GaN layer, The lower surface of the n-type GaN layer is in contact with the upper surface of the substrate; thermal annealing is performed on the LED wafer on which the first thin film is evaporated, so that the first thin film forms an ohmic contact with the p-type GaN layer; A second film is deposited on the upper surface of the first film, and the lower surface of the second film is in contact with the first film; a plurality of auxiliary nano-patterns are prepared on the upper surface of the second film; The nanopattern etches the second thin film to form a plurality of masks; the first thin film, the p-type GaN layer, the quantum well active layer and the n-type GaN layer are etched through the masks to form a plurality of masks; LED nano-columns, two ends of the LED nano-columns are used to connect with electrodes, a first electrode is prepared at the end of the LED nano-columns that carries the first thin film, and a first electrode is prepared at the end of the LED nano-column that carries the first film, and the n-type GaN layer of the LED nano-columns A second electrode is prepared at one end to form a nano-pillar LED device, wherein the quantum well active layer is not in contact with the first electrode and the second electrode, since the first thin film has conductivity, and the first thin film has been connected to the p The GaN layer forms a good ohmic contact, thereby increasing the area of ohmic contact between the p-type GaN layer and the electrode, and achieving the technical effect of improving the p-type ohmic contact performance of the nano-LED.

Note that the above are only preferred embodiments of the present invention and applied technical principles. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described herein, and various obvious changes, readjustments and substitutions can be made by those skilled in the art without departing from the protection scope of the present invention. Therefore, although the present invention has been described in detail through the above embodiments, the present invention is not limited to the above embodiments, and can also include more other equivalent embodiments without departing from the concept of the present invention. The scope is determined by the scope of the appended claims.

Claims (10)

1. A method for preparing a nano-pillar, comprising:

evaporating a first thin film on the upper surface of an L ED wafer, wherein the L ED wafer comprises a p-type GaN layer, a quantum well active layer, an n-type GaN layer and a substrate, the upper surface of the p-type GaN layer serves as the upper surface of the L ED wafer, the lower surface of the p-type GaN layer is in contact with the upper surface of the quantum well active layer, the lower surface of the quantum well active layer is in contact with the upper surface of the n-type GaN layer, and the lower surface of the n-type GaN layer is in contact with the upper surface of the substrate;

performing thermal annealing treatment on the L ED wafer evaporated with the first thin film to enable the first thin film and the p-type GaN layer to form ohmic contact;

depositing a second film on the upper surface of the first film, wherein the lower surface of the second film is in contact with the first film;

preparing a plurality of auxiliary nano patterns on the upper surface of the second film;

etching the second film through the auxiliary nano-patterns to form a plurality of masks;

and etching the first film, the p-type GaN layer, the quantum well active layer and the n-type GaN layer through the mask to form a plurality of L ED nano-pillars, wherein two ends of the L ED nano-pillars are used for being connected with electrodes.

2. The method of claim 1, wherein said etching the second film through the auxiliary nanopattern to form a plurality of masks comprises:

spraying a first etching gas along a first target direction, wherein the first target direction is a direction vertical to the upper surface of the second film, and the auxiliary nano pattern is used for blocking the first etching gas;

and the second film forms a plurality of masks under the etching of the first etching gas.

3. The method of claim 2, wherein the first etching gas is CHF₃Or O₂。

4. The method of claim 1, wherein the etching the first film, the p-type GaN layer, the quantum well active layer, and the n-type GaN layer through the mask to form a plurality of L ED nanopillars comprises:

injecting a second etching gas along a second target direction, wherein the second target direction is a direction vertical to the upper surface of the first film, and the mask is used for blocking the second etching gas;

the first film, the p-type GaN layer, the quantum well active layer and the n-type GaN layer form a plurality of middle nano columns under the etching of the second etching gas;

the mask of the intermediate nanopillars is removed to form a plurality L ED nanopillars.

5. The method of claim 4, wherein the second etching gas is Cl₂Or Cl₃B。

6. The method of claim 1, wherein the removing the mask of the intermediate nanopillars to form a plurality L ED nanopillars comprises:

the mask is removed by hydrofluoric acid to form a plurality of L ED nanopillars.

7. The method of any of claim 1, wherein the first film is a silicon oxide film.

8. The method of any of claim 1, wherein the second film is an ITO film.

9. The method according to any one of claims 1 to 8, wherein the thermal annealing treatment is carried out at a temperature of 650 ℃ to 850 ℃ and for an annealing time of 0.5 minutes to 10 minutes.

10. A method for preparing a nano-pillar L ED device, comprising:

evaporating a first thin film on the upper surface of an L ED wafer, wherein the L ED wafer comprises a p-type GaN layer, a quantum well active layer, an n-type GaN layer and a substrate, the upper surface of the p-type GaN layer serves as the upper surface of the L ED wafer, the lower surface of the p-type GaN layer is in contact with the upper surface of the quantum well active layer, the lower surface of the quantum well active layer is in contact with the upper surface of the n-type GaN layer, and the lower surface of the n-type GaN layer is in contact with the upper surface of the substrate;

performing thermal annealing treatment on the L ED wafer evaporated with the first thin film to enable the first thin film and the p-type GaN layer to form ohmic contact;

depositing a second film on the upper surface of the first film, wherein the lower surface of the second film is in contact with the first film;

preparing a plurality of auxiliary nano patterns on the upper surface of the second film;

etching the second film through the auxiliary nano-patterns to form a plurality of masks;

etching the first film, the p-type GaN layer, the quantum well active layer and the n-type GaN layer through the mask to form a plurality of L ED nano-pillars, wherein two ends of the L ED nano-pillars are used for being connected with electrodes;

a first electrode was fabricated at one end of the L ED nanopillar carrying the first thin film, and a second electrode was fabricated at one end of the n-type GaN layer of the L ED nanopillar to form a nanopillar L ED device, wherein the quantum well active layer was not in contact with the first and second electrodes.

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