KR20110096897A - Method for manufacturing p-type gan-based compound semiconductor, method for actvating p-type dopant contained in gan-based compound semiconductor, gan-based compound semiconductor device, and gan-based compound semiconductor light-emitting device - Google Patents

Abstract

The present invention increases the hole concentration and improves the electrical properties of a p-type gallium nitride compound semiconductor layer by activating the p-type dopant contained in the gallium nitride compound semiconductor using an electrochemical potentiostatic method. It is intended to provide a method which can be done and to provide a gallium nitride compound semiconductor device and a light emitting device manufactured using the method.

Description

A method of manufacturing a X-type gallium nitride compound semiconductor, a method of activating a X-type dopant contained in a gallium nitride compound semiconductor, a gallium nitride compound semiconductor device and a gallium nitride compound semiconductor light emitting device {METHOD FOR MANUFACTURING P-TYPE GaN-BASED COMPOUND SEMICONDUCTOR, METHOD FOR ACTVATING P-TYPE DOPANT CONTAINED IN GaN-BASED COMPOUND SEMICONDUCTOR, GaN-BASED COMPOUND SEMICONDUCTOR DEVICE, AND GaN-BASED COMPOUND SEMICONDUCTOR LIGHT-EMITTING DEVICE}

The present application relates to a method for manufacturing a p-type gallium nitride compound semiconductor, a method for activating a p-type dopant contained in a gallium nitride compound semiconductor, a gallium nitride compound semiconductor device and a gallium nitride compound semiconductor light emitting device will be.

Mg-doped p-type GaN thin films are used as hole supply layers in green, blue and UV light emitting diodes and laser diodes. In general, the n-type GaN layer exhibits sufficient carrier (electron) concentration (˜5 × 10 ¹⁸ cm ⁻³ ) to fabricate a GaN-based optoelectronic device. The carrier concentration of the p-GaN layer should be similar to the n-GaN layer but is still one order lower (~ 5 x 10 ¹⁷ cm ^-3 ) despite the technology development over the last decade. Since Amano et al. Succeeded in activating p-type GaN using low energy electron-beam irradiation for the first time, several methods have been studied to improve the degree of activation. Nakamura et al. Have developed a thermal annealing method of 700 ° C. or higher in an inert gas atmosphere, and at present, most chips are fabricated by activating p-GaN thin films based on these post-annealing methods. Several modified methods have been studied and the p-GaN properties can be improved by modification of subsequent heat treatment methods. Thermal annealing in an oxygen gas mixture, multi-stage annealing, annealing with hydrogen-storage metal layers, and annealing with minority carrier injection have been studied, and the hole concentration has been increased by about 30-50% using this simple modification method.

However, the hole concentration could be improved by ˜30% by using KrF (248 nm) excimer-laser irradiation as the activation energy source, but out-diffusion of Ga occurs due to high energy irradiation.

The Mg-doped GaN layer formed by organometallic chemical vapor deposition (MOCVD) is electrically passivated because Mg atoms bond with H atoms during the deposition process. An activation process is necessary to break the Mg-H bond and remove H atoms from the lattice. The activation process is a forward reaction of the formula:

^{(Mg-H) 0 ↔ Mg} - + H +

Basically, the reaction is reversible and the forward reaction is accelerated when H ⁺ ions are removed from the lattice. Conventional thermal annealing could be used to remove H atoms from the p-GaN layer and to bring the hole concentration to 1 × 10 ¹⁸ cm ⁻³ or more. However, a high temperature of 800 ° C. or higher is required to remove H atoms, and nitrogen vacancies are created by the thermal annealing process. As a result, the electrical and optical properties of the p-GaN layer deteriorate in device performance even if high hole concentrations are achieved.

The present invention increases the hole concentration and improves the electrical properties of a p-type gallium nitride compound semiconductor layer by activating the p-type dopant contained in the gallium nitride compound semiconductor using an electrochemical potentiostatic method. It is intended to provide a method which can be done, and to provide a gallium nitride compound semiconductor device and a light emitting device manufactured using the method.

However, the problem to be solved by the present application is not limited to the above-mentioned problem, and other problems not mentioned will be clearly understood by those skilled in the art from the following description.

In order to achieve the above object, an aspect of the present application, forming a gallium nitride compound semiconductor layer comprising a p-type dopant on a substrate; Contacting the substrate on which the gallium nitride compound semiconductor layer is formed with an electrolyte solution; Providing a counter electrode in contact with the electrolyte; And activating the p-type dopant by applying a voltage between the counter electrode and the gallium nitride compound semiconductor layer as a working electrode: manufacturing a p-type gallium nitride compound semiconductor; Provide a method.

In another aspect of the present invention, a substrate on which a gallium nitride compound semiconductor including a p-type dopant is formed is contacted with an electrolyte solution; Providing a counter electrode in contact with the electrolyte; And activating the p-type dopant by applying a voltage between the counter electrode and the gallium nitride compound semiconductor layer as a working electrode. A method of activating a p-type dopant is provided.

Another aspect of the present application provides a gallium nitride compound semiconductor device comprising a p-type gallium nitride compound semiconductor manufactured by the method for producing the p-type gallium nitride compound semiconductor.

Another aspect of the present application, an n-type gallium nitride compound semiconductor layer formed on a substrate; An active layer formed on the n-type gallium nitride compound semiconductor layer; And a gallium nitride-based compound semiconductor layer comprising a p-type dopant formed on the active layer, the p-type dopant comprising: contacting the laminate with an electrolyte solution; Providing a counter electrode in contact with the electrolyte; A light emitting device, which is activated by applying a voltage between the counter electrode and a gallium nitride based compound semiconductor layer comprising the p-type dopant as a working electrode.

According to the present invention, the p-type dopant is activated by directly applying a voltage to a gallium nitride compound semiconductor layer including a p-type dopant by using an electrochemical potentioelectric method to obtain a p-type gallium nitride compound semiconductor layer. It is possible to effectively improve the hole concentration, and also obtain optically and electrically high luminous intensity, high mobility and low resistance H degree. Therefore, the gallium nitride compound semiconductor including the p-type dopant activated by the present invention has a high hole concentration, a low resistance, and the like as described above, thereby providing various semiconductor devices and various light emission such as light emitting diodes and laser diodes. When the device is manufactured, the forward threshold voltage can be lowered, thereby reducing the power consumption when driving the device, and the high carrier concentration can increase the mobility of holes to increase the external quantum efficiency and obtain high brightness.

1 is a schematic view showing a processing apparatus used in a process for activating a p-type dopant included in a gallium nitride compound semiconductor layer in a method of manufacturing a p-type gallium nitride compound semiconductor according to an embodiment of the present application. ,
2 is a cross-sectional view illustrating a layer structure of a light emitting diode as an example of a p-type gallium nitride compound semiconductor device according to an embodiment of the present disclosure;
3 is a cross-sectional view showing a layer structure of a model of a gallium nitride compound semiconductor device manufactured according to one embodiment of the present application;
4 is a result of analyzing the hole concentration after activation of the p-type dopant according to various applied voltages in the embodiment of the present application,
FIG. 5 is an SEM image of a surface of a p-type gallium nitride compound semiconductor layer activated at an applied voltage of 9 V according to an embodiment of the present disclosure.
Figure 6a is N ₂ for 10 minutes in the comparative example of the present application Secondary ion mass spectrometry (SIMS) depth profile of a p-type gallium nitride compound semiconductor layer activated by thermal annealing at 650 ° C. under an atmosphere,
6B is a secondary ion mass spectrometry (SIMS) depth profile of a p-type gallium nitride based layer activated using an electrochemical potentiometry at an applied voltage of 7 V,
7 is a cross-sectional view showing a layer structure of a model of a gallium nitride compound semiconductor device manufactured according to an embodiment of the present application;
8 is a photograph showing a p-type electrode in a TCL pattern according to an embodiment of the present application;
FIG. 9 is a graph showing EL results according to conditions in one embodiment of the present application;
10 is a photograph showing a light emitting diode chip packaged in 3528PLCC 2type according to one embodiment of the present application;
11A is a graph showing the number of chips for Vf at 20 mA by probing the entire wafer in one embodiment of the present application.
FIG. 11B is a graph showing an average Vf value according to the current time of one wafer in one embodiment of the present application. FIG.
12 is a full probing map (full probing map) data according to the current time in an embodiment of the present application,
FIG. 13 is a graph illustrating IV measurement results of chips having a wavelength of 463 nm (± 1 nm) according to current time according to an embodiment of the present disclosure.

DETAILED DESCRIPTION Hereinafter, exemplary embodiments and embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art may easily implement the present invention.

It should be understood, however, that the present invention may be embodied in many different forms and is not limited to the embodiments and examples described herein. In the drawings, parts irrelevant to the description are omitted for simplicity of explanation, and like reference numerals designate like parts throughout the specification.

Throughout this specification, when a part is said to "include" a certain component, it means that it can further include other components, without excluding the other components unless specifically stated otherwise.

As used throughout this specification, the terms "about", "substantially", and the like, are used at, or in close proximity to, numerical values when a manufacturing and material tolerance inherent in the stated meanings is given, and an understanding of the invention Accurate or absolute figures are used to help prevent unfair use by unscrupulous infringers.

As used throughout this specification, the term "electrolyte" may be interpreted to mean a solution containing an electrolyte, an electrolyte in a molten state, or a flowable material including the same.

As used throughout this specification, the term "gallium nitride compound semiconductor" may be interpreted to mean a semiconductor including Ga and N elements as a doped or undoped gallium nitride compound semiconductor.

As used throughout this specification, an "alkali metal" may be interpreted to include a metal belonging to an alkali metal group of the periodic table, and an "alkalito metal" may include a metal belonging to an alkaline earth metal group of the periodic table. It can be interpreted as.

Hereinafter, a method of manufacturing a p-type gallium nitride compound semiconductor, a method of activating a p-type dopant contained in a gallium nitride compound semiconductor, a gallium nitride compound semiconductor device, and a gallium nitride compound semiconductor light emitting device Embodiments are described with reference to the accompanying drawings, wherein the referenced numbers represent corresponding or identical elements in the various drawings. However, the present application is not limited by these embodiments.

In one aspect of the present application, a method of manufacturing a p-type gallium nitride compound semiconductor comprises: forming a gallium nitride compound semiconductor layer comprising a p-type dopant on a substrate; Contacting the substrate on which the gallium nitride compound semiconductor layer is formed with an electrolyte solution; Providing a counter electrode in contact with the electrolyte; And activating the p-type dopant by applying a voltage between the counter electrode and the gallium nitride compound semiconductor layer as a working electrode. For example, when the substrate on which the gallium nitride compound semiconductor layer is formed is in contact with an electrolyte, some or all of the substrate may be in contact with the electrolyte, but is not limited thereto.

Herein, contacting the substrate on which the gallium nitride compound semiconductor layer is formed with an electrolyte may be interpreted to mean contacting part or all of the substrate on which the gallium nitride compound semiconductor layer is formed with the electrolyte, but It is not limited. Here, the method of contacting the substrate on which the gallium nitride compound semiconductor layer is formed with the electrolyte is not particularly limited.

In exemplary implementations, various substrates having a resistivity of less than 10 ⁻⁶ Ω · cm may be used as the substrate, but are not limited thereto. For example, the substrate may be non-conductive, but is not limited thereto. For example, the substrate may be Al ₂ O ₃ , Ga ₂ O _{3 ,} Si or It may include SiC, or may include a GaN thick film, but is not limited thereto. For example, as a non-limiting example of the substrate, Al ₂ O ₃ , such as sapphire and the like, is non-conductive and has a hexagonal structure like gallium nitride, and the crystallographic structures of (0001) faces are similar to each other. In addition, Al ₂ O ₃ is hard to have a high Mohs hardness of 9 and a very high melting point of 2050 ° C., which is suitable as a thin film substrate to be deposited at a high temperature such as gallium nitride. In addition, since it is not easily corroded by acids or alkalis, it has the advantages of being able to withstand various wet etching required for the light emitting diode manufacturing process and having a low price. SiC is widely used as a substrate for growing gallium nitride thin films because of its low lattice mismatch and excellent thermal properties. When using a non-conductive substrate as described above, the p-type dopant is further applied by directly applying a voltage to the gallium nitride compound semiconductor layer by using the gallium nitride compound semiconductor layer as a working electrode. It can be activated efficiently.

In example embodiments, a low-growth buffer layer formed of gallium nitride (GaN), aluminum nitride (AlN), or the like may be formed on the substrate to further improve the crystal quality of the gallium nitride compound semiconductor. It may be, but is not limited thereto. In addition, a dislocation reduction technique such as lateral growth or facet-controlled growth may be used.

In exemplary embodiments, the p-type dopant may be selected from the group consisting of Mg, Zn, Cd, Be, Ca, Ba, and combinations thereof. It is not limited to this.

In exemplary embodiments, the gallium nitride based compound semiconductor layer including the p-type dopant may be formed on the substrate using a vapor-phase deposition method, but is not limited thereto.

For example, the vapor deposition method may be a metal organic chemical vapor deposition (MOCVD) method, a molecular beam epitaxy (MBE) method, or a hydrogen vapor phase epitaxy (HVPE) method. Etc., but is not limited thereto. For example, when using the MOCVD method, a source gas for a gallium nitride compound and / or a source gas for a p-type dopant is injected into the substrate while maintaining the substrate at a predetermined temperature. By causing a chemical reaction to form the gallium nitride compound semiconductor, a gallium nitride compound semiconductor layer having a predetermined composition and / or a gallium nitride compound semiconductor layer containing a p-type dopant is deposited on the substrate.

The gallium nitride compound semiconductor layer may be directly formed on the surface of the substrate, or may be formed on the surface of the low-temperature growth buffer layer previously formed on the surface of the substrate. Further, when the gallium nitride compound semiconductor layer is one of a plurality of layered semiconductor layers constituting the gallium nitride compound semiconductor device, the gallium nitride compound semiconductor layer is formed on the surface of the semiconductor layer immediately below it. May be, but is not limited thereto.

In exemplary embodiments, as the gallium nitride compound semiconductor, gallium nitride (GaN), aluminum gallium nitride (Al _x Ga _{1 - x} N), indium gallium nitride (In _x Ga _{1 - x} N), indium aluminum gallium nitride (AlGaInN) and the like, but are not limited thereto.

In exemplary embodiments, for example, the p-type gallium nitride compound semiconductor may include a laminated structure of two or more layers having different compositions, content of p-type dopants, and the like, but is not limited thereto.

1 is a schematic view showing a processing apparatus used in a process of activating a p-type dopant included in a gallium nitride compound semiconductor layer in a method of manufacturing a p-type gallium nitride compound semiconductor according to an embodiment of the present application. . As shown in FIG. 1, a processing apparatus used in a process of activating a p-type dopant using an electrochemical potentiometry according to an embodiment of the present disclosure may contain an electrolyte 400 and at the same time the electrolyte ( An electrolytic cell 500 for contacting the substrate 100 on which the gallium nitride compound semiconductor layer 200 containing the p-type dopant 200 with the p-type dopant and the counter electrode 300 is in contact with the electrolyte, and the working electrode (or the anode). A power source 600 for applying a constant voltage between the gallium nitride compound semiconductor layer 200 containing the p-type dopant and the counter electrode (or the cathode) 300, and the power source 600; a wiring 700 for connecting the gallium nitride compound semiconductor layer 200 containing a p-type dopant, and a wiring 800 for connecting the power supply 600 and the counter electrode 300. . If necessary, a thermocouple (not shown) for monitoring the temperature of the electrolyte solution 400 may be provided in the electrolytic cell 500. The thermocouple indirectly senses the temperature of the substrate 100. Meanwhile, if necessary, a reference electrode made of a material such as Hg / HgO may be disposed between the working electrode and the counter electrode, but is not limited thereto.

In exemplary embodiments, the electrolyte may be provided in a solution form or a molten salt form, but is not limited thereto.

When the electrolyte is in the form of a solution, the electrolyte may be a conductive solution having acidity, neutrality or alkalinity. For example, the electrolyte may be an aqueous solution including an acidic, neutral or alkaline electrolyte, but is not limited thereto. The acid electrolyte may include an acid, and the acid is not particularly limited. Examples of the acid electrolyte include, but are not limited to, HCl, HF, HBr, HI, H ₂ SO ₄ , H ₂ CO ₃ , or a mixture thereof. Can be mentioned. The alkaline electrolyte may include one or more alkaline metal salts, and the alkali metal salt is not particularly limited, and examples thereof include salts of alkali metals, salts of alkali metals, and the like. Examples of the salt of the alkali metal and the salt of the alkali metal include, for example, hydroxides of alkali metals or alkaline earth metals, halides of alkali metals or alkaline earth metals, and the like. no. Halide of the metal means chloride, fluoride, bromide or the like of the metal.

When the electrolyte is in the form of a molten salt, the electrolyte may include a halide of a molten alkali metal, a halide of an alkaline earth metal, or a mixture thereof, but is not limited thereto. For example, the halide of the alkali metal or alkaline earth metal means a chloride, fluoride, bromide, or the like of the alkali metal.

As the counter electrode, various materials which do not elute in the electrolyte when a voltage is applied between the p-type gallium nitride compound semiconductor layer can be selected and used. For example, the counter electrode may be manufactured using one or more selected from the group consisting of platinum, platinum-plated titanium, lead, copper, tin, and graphite, but is not limited thereto.

The power source may use a typical constant voltage system to which forward voltage is applied.

In example embodiments, the method may further include heat treating the substrate on which the gallium nitride compound semiconductor layer is formed before contacting the electrolyte, but is not limited thereto. For example, the heat treatment temperature may be 500 ° C. or higher, for example, about 500 ° C. to 700 ° C., but is not limited thereto. The heat treatment may be used without particular limitation in the range of heat treatment methods and heat treatment temperatures known in the art, for example, may be performed using heating, ultraviolet rays, or RF, but is not limited thereto.

In the step of activating the p-type dopant by the electrochemical electrostatic potential method using the processing apparatus, the power supply 600 is connected via the wirings 7, 8, and the substrate 100 and the counter electrode 4 are connected. Respectively, a constant voltage is applied from the power supply 600 between the p-type gallium nitride compound semiconductor layer 200 and the counter electrode 300 in contact with the electrolyte solution 400 contained in the electrolytic cell 500. In response to such voltage application, the p-type dopant contained in the gallium nitride compound semiconductor layer 200 is dehydrogenated and activated by electrochemical potentiometry, thereby producing a p-type gallium nitride compound semiconductor. do.

In the activation process using the electrochemical potentiometric method, by monitoring the temperature of the electrolyte 400 using a thermocouple, the temperature of the gallium nitride compound semiconductor layer 200 calculated from the value measured by the thermocouple is solder (solder) It is preferable to control the voltage value applied between the both electrodes so that they can be adjusted in a range not exceeding the melting point, such as). The controller may control the temperature of the substrate to a preset target temperature. In addition, although not shown in the drawings, the device may be designed to cool the electrolyte 400 from the outside of the electrolytic cell 500.

The value of the applied voltage differs depending on the composition and thickness of the gallium nitride compound semiconductor, the type and amount of the p-type dopant, the type and concentration of the electrolyte, and the like, and cannot be specified. Preferably, in the activation process using the electrochemical electrostatic potential method, as described above, the voltage value is adjusted in a range in which the temperature of the substrate 100 does not exceed the melting point, and the gallium nitride compound semiconductor layer is in accordance with the voltage value. The voltage application time can be set so that almost all the dehydrogenation of the p-type dopant added to (200) occurs.

In the method of manufacturing the p-type gallium nitride compound semiconductor according to the embodiment of the present application, the working electrode is in contact with a substrate on which a gallium nitride compound semiconductor layer containing a p-type dopant is formed. Using a gallium nitride compound semiconductor layer containing the p-type dopant, and applying a voltage between the counter electrode provided in contact with the electrolyte solution to the gallium nitride compound semiconductor. The p-type dopant contained can be activated by a dehydrogenation reaction. In the method of manufacturing the p-type gallium nitride compound semiconductor according to an embodiment of the present application, by the activation of the p-type dopant hole concentration to about 5 x 10 ¹⁷ to about 5 x 10 ¹⁹ cm ^-3 Can be improved.

When a voltage is applied between the gallium nitride compound semiconductor layer containing the p-type dopant as the working electrode and the counter electrode, electrons (e ⁻ ) are supplied from the electrolyte to the gallium nitride compound semiconductor formed on the substrate, Hydrogen ions (H ⁺ ) are generated by breaking the bond between the p-type dopant and hydrogen by the supplied electrons. Since the generated hydrogen ions are released from the semiconductor due to the potential difference with the counter electrode, the concentration of hydrogen ions in the semiconductor decreases. Thus, the p-type dopant appears to be dehydrogenated. Hydrogen ions emitted from the semiconductor are transported to the counter electrode and electrons are received by the counter electrode surface to generate hydrogen molecules (H ₂ ).

In addition, when the electrolyte solution contains hydroxide ions (OH ⁻ ), the hydroxide ions are attracted by the surface of the gallium nitride compound semiconductor layer, emit electrons from the surface, and combine with the hydrogen ions in the semiconductor. Produces water molecules (H ₂ O). As a result, the concentration of hydrogen ions in the semiconductor is reduced. In this way, the p-type dopant appears to be dehydrogenated.

In addition, in the method of manufacturing the p-type gallium nitride compound semiconductor according to the embodiment of the present application, a power source for applying power to at least a substrate and a counter electrode to perform the activation process, and the substrate or the electrolyte solution. There must be an electrolytic cell to accommodate the back. The activation treatment can be carried out at a relatively low temperature below the boiling point of the electrolyte under normal pressure. Therefore, the initial cost and operating cost of the said activation processing apparatus can be reduced. Further, for example, a plurality of substrates may be provided in the electrolyte at the same distance from the counter electrode, so that the gallium nitride compound semiconductor layers on the plurality of substrates may be substantially uniformly activated at once without variations. .

Further, as the activation treatment is performed in the electrolyte solution, the temperature rise of the gallium nitride compound semiconductor layer is suppressed during the activation treatment. The composition of the semiconductor is not changed by nitrogen release or the like. Since the metal ions contained in the electrolyte are attracted to the counter electrode side during the activation process as cations, the semiconductor is not contaminated by the electrolyte or the like contained in the electrolyte. Gallium nitride compound semiconductors such as gallium nitride, aluminum gallium nitride, and indium gallium nitride are usually difficult to wet etch, and therefore are not etched by the electrolyte solution used in the activation process. Therefore, in the method of manufacturing the p-type gallium nitride compound semiconductor according to the embodiment of the present application, the gallium nitride compound semiconductor can be prevented from being damaged during the activation process.

In addition, the activation process is performed while the electrolyte solution is in contact with substantially the entire surface of the gallium nitride compound semiconductor layer. Thus, for example, the semiconductor layer is formed in a thin film form on a substrate, and swelling, warpage, irregularities, etc., in a multilayer structure including the substrate and the thin film of the semiconductor are Even if present, the multilayer structure can be broken and the p-type dopant in the semiconductor can be uniformly activated without variation in the degree of activation of the p-type dopant.

Accordingly, in the method of manufacturing the p-type gallium nitride compound semiconductor according to the embodiment of the present application, by incorporating the various effects, the p-type gallium nitride compound semiconductor is cheaper and more efficiently produced in large quantities It becomes possible. A gallium nitride compound semiconductor including a p-type dopant may be efficiently and uniformly activated without composition change or contamination, thereby obtaining substantially constant semiconductor quality. Therefore, it may be possible to reduce the manufacturing cost of the p-type gallium nitride compound semiconductor.

In the method of manufacturing the p-type gallium nitride compound semiconductor according to an aspect of the present application, the gallium nitride compound semiconductor layer including the p-type dopant is formed on the non-conductive substrate such as sapphire according to the vapor phase growth method In this case, the activation efficiency of the p-type dopant may be improved by directly applying a voltage to the gallium nitride compound semiconductor layer including the p-type dopant as a working electrode.

According to another aspect of the present invention, a method of activating a p-type dopant contained in a gallium nitride compound semiconductor comprises contacting a substrate on which a gallium nitride compound semiconductor including a p-type dopant is formed with an electrolyte solution; Providing a counter electrode in contact with the electrolyte; And activating the p-type dopant by applying a voltage between the counter electrode and the gallium nitride compound semiconductor layer as a working electrode. In this regard, all of the above descriptions of the method for manufacturing the p-type gallium nitride compound semiconductor according to one aspect of the present application are contained in the p-type dopant contained in the gallium nitride compound semiconductor according to the other aspect of the present application. It can be applied to the activation method of.

In another aspect of the present application, the gallium nitride compound semiconductor device may include a p-type gallium nitride compound semiconductor manufactured according to the method for producing a p-type gallium nitride compound semiconductor of the present application as described above. . Since such a device includes a p-type gallium nitride compound semiconductor manufactured according to the manufacturing method of the p-type gallium nitride compound semiconductor of the present application as described above, excellent characteristics such as light emitting diodes, laser diodes, etc. In the case of the light emitting device, excellent brightness and the like can be obtained.

For example, when manufacturing a light emitting device using the manufacturing method of the p-type gallium nitride compound semiconductor according to an embodiment of the present application, the p-type gallium nitride compound semiconductor to form a light emitting device on a substrate The p-type dopant may be activated by the electrochemical potentiometric method as described above in the form of a layer and a plurality of other layers by vapor deposition.

In another aspect of the present application, the light emitting device comprises: an n-type gallium nitride based compound semiconductor layer formed on a substrate; An active layer formed on the n-type gallium nitride compound semiconductor layer; And a gallium nitride-based compound semiconductor layer comprising a p-type dopant formed on the active layer, the p-type dopant comprising: contacting the laminate with an electrolyte solution; Providing a counter electrode in contact with the electrolyte; It may be activated by applying a voltage between the counter electrode and the gallium nitride compound semiconductor layer containing the p-type dopant as a working electrode. The structure of the light emitting device is not particularly limited and may be one having a structure known in the art.

All of the contents described for the manufacturing method of the p-type gallium nitride compound semiconductor can be applied to the light emitting device according to another aspect of the present application.

2 is a cross-sectional view showing a layer structure of a light emitting diode in an embodiment of the light emitting device of the present application.

Referring to FIG. 2, a light emitting diode according to an embodiment of the present disclosure includes a low-temperature growth buffer layer 120, an n-type gallium nitride based compound semiconductor layer 130 stacked in order on a surface 110 of a substrate 100, It may include, but is not limited to, an intermediate layer 140, a light emitting layer 150, and a laminate including the p-type gallium nitride compound semiconductor layer 200 activated as described above. An electrode pad 220 is formed on a portion of the surface 210 of the p-type gallium nitride compound semiconductor layer 200. In addition, a portion of the n-type gallium nitride compound semiconductor layer 130 is exposed by removing a portion of the intermediate layer 140, the light emitting layer 150, and the p-type gallium nitride compound semiconductor layer 200. The electrode pads 240 are formed on the exposed surface 230.

As the low-temperature growth buffer layer 260, for example, a layer formed of gallium nitride, aluminum nitride, or the like may be used, but is not limited thereto. The n-type gallium nitride compound semiconductor layer 130 may include, but is not limited to, a layer formed of gallium nitride including silicon (Si) as an n-type dopant. have. The intermediate layer 140 may include a layer formed of indium gallium nitride (In _x Ga _1-xN ) as a layer for improving the crystal quality of the emission layer 150, but is not limited thereto.

An example of the light emitting layer 150 may be a multiple quantum well (MQW) layer, which is a superlattice device, for example a barrier layer formed of gallium nitride. And a well layer formed of indium gallium nitride (In _x Ga _1-x N) are alternately stacked, or indium gallium nitride (In _x Ga _1-x N) each having a different composition x. The barrier layer and the well layer formed may be alternately stacked so that the barrier layer may be disposed as the uppermost layer and the lowermost layer of the laminate.

The p-type gallium nitride compound semiconductor layer 200 is, for example, magnesium (Mg) and the like is added as a p-type dopant, such a p-type dopant to the manufacturing method according to one aspect of the present application A layer formed of gallium nitride (GaN) or aluminum gallium nitride (Al _x Ga _1-x N) activated by the above may be used, but is not limited thereto.

As an example of the electrode pad 20, a laminate including a nickel layer stacked on the surface 210 of the p-type gallium nitride compound semiconductor layer 200 and a gold (Au) layer stacked on the nickel layer. It may be, but is not limited thereto. Examples of the electrode pad 220 include a titanium (Ti) layer, an aluminum layer, a nickel layer, and a gold layer that are sequentially stacked on the exposed surface 230 of the n-type gallium nitride compound semiconductor layer 130. The laminate may be, but is not limited thereto.

Each layer from the low-temperature growth buffer layer 120 to the p-type gallium nitride compound semiconductor layer 200 is, for example, by a vapor-phase deposition method such as the MOCVD method described above. Can be formed. That is, the substrate 100 is introduced into a chamber of the apparatus for performing the MOCVD, and the source gas for forming each layer is introduced into the chamber while maintaining the temperature of the substrate 100 at a temperature suitable for the growth of each layer. By injecting, as described above, a chemical reaction occurs on the substrate or the lower layer of each formed layer, thereby depositing a gallium nitride compound having a predetermined composition. By repeating this process for each layer, a laminate 250 including the p-type gallium nitride compound semiconductor layer 200 is formed from the low-temperature growth buffer layer 120 formed on the substrate.

An example of a source gas for gallium, which is injected into the chamber, may include, but is not limited to, trimethyl gallium [Ga (CH ₃ ) ₃ ]. Examples of source gas for nitrogen include, but are not limited to, ammonia (NH ₃ ). Examples of the source gas for magnesium (Mg) include, but are not limited to, biscyclopentadienyl magnesium [Mg (C ₅ H ₅ ) ₂ ], and the like.

Referring to FIG. 1, after forming the laminate 250, the wire 700 is connected to the p-type gallium nitride compound semiconductor layer 200 from the power source 600, and the activation process described above is performed. do. As a result, the p-type dopant contained in the p-type gallium nitride compound semiconductor layer 200 in the laminate 250 is activated by dehydrogenation by the apparatus described above.

Subsequently, a part of the intermediate layer 140, the light emitting layer 150, and the p-type gallium nitride compound semiconductor layer 200 is removed by, for example, combining a photolithography process and a dry etching or wet etching process. A portion of the surface 230 of the n-type gallium nitride based semiconductor layer 130 is exposed. Thereafter, a photolithography process, an evaporation method, a lift-off, and the like are combined to expose the surface of the p-type gallium nitride compound semiconductor layer 200 and the n-type exposed as described above. By forming electrode pads 220 and 240 on each of the surfaces 230 of the gallium nitride compound semiconductor layer 130, a light emitting diode as shown in FIG. 2 is manufactured.

In practice, a plurality of light emitting devices can be manufactured by a process described later using a substrate 100 (wafer = wafer) large enough to support a plurality of light emitting devices. That is, the laminate 250 is formed on the surface of the wafer-shaped substrate 100, and then the p-type included in the p-type gallium nitride compound semiconductor layer 200 in the laminate 250. The dopant is activated by dehydrogenation by an electrochemical potentiostatic method according to the method for producing the p-type gallium nitride compound semiconductor of the present application.

Next, in each of the light emitting device regions, predetermined portions of the intermediate layer 140, the light emitting layer 150, and the p-type gallium nitride compound semiconductor layer 200 are removed to remove the n-type gallium nitride compound semiconductor layer ( A portion of the surface 230 of 130 is exposed, the surface 210 of the p-type gallium nitride based compound semiconductor layer 200 and the surface 230 of the exposed n-type gallium nitride based compound semiconductor layer 130 ), Electrode pads 220 and 240 are formed in each. Then, the respective areas are cut and separated. In this way, a plurality of light emitting devices are manufactured.

In the light emitting device, when a current is applied between the electrode pads 220 and 240, holes are injected from the electrode pad 220 into the p-type gallium nitride compound semiconductor layer 200, and the electrode pad ( Electrons injected into the n-type gallium nitride compound semiconductor layer 130 from 240 are transported toward the electrode pad 220 through the n-type gallium nitride compound semiconductor layer 130 and the intermediate layer 140. . Accordingly, the holes and the electrons recombine in the emission layer 150, and the gallium nitride compound forming the emission layer 150 is excited to emit light.

The present invention is not limited to the examples described with reference to the drawings, and may be variously changed without departing from the gist of the present application. For example, as described above, the gallium nitride compound semiconductor layer 200 formed on the plurality of substrates 100 by contacting the plurality of substrates 100 with the electrolyte 400 as described above. It can be activated at the same time. In this case, the substrates 100 may be disposed at the same distance from the counter electrode 300 so that no deviation occurs in the activation process. Alternatively, the counter electrode 300 may be prepared for each substrate 100, and each counter electrode 300 may be disposed at the same distance from each substrate 100. In addition, for example, the inner surface of the electrolytic cell 500 may be formed of a conductive material, connected to the power supply 600, and the counter electrode 300 may be omitted. In addition, according to the manufacturing method of the p-type gallium nitride compound semiconductor of the present application, the activation method of the p-type dopant by electrochemical potentiostatic method is applied to the structures of gallium nitride compound semiconductor devices, gallium nitride compound light emitting devices and the like. The present invention can be applied to various gallium nitride compound semiconductor devices, gallium nitride compound light emitting devices, and the like, which are not limited and manufactured by various methods known in the art. For example, a method of activating a p-type dopant by an electrochemical potentiostatic method according to the manufacturing method of the p-type gallium nitride compound semiconductor of the present application is to activate the p-type dopant in the light emitting device according to FIG. 7. It may be applied to, but is not limited thereto.

The p-type gallium nitride compound semiconductor manufactured by the method for manufacturing the p-type gallium nitride compound semiconductor according to the present application may be included in a light emitting device and other gallium nitride compound semiconductor devices.

The gallium nitride-based compound semiconductor devices of the present application include light-receiving devices such as photodetectors and flame sensors; Field Effect Transistors (FETs), Metal-Semiconductor FETs (MESFETs), Metal-Insulator-Semiconductor FETs (MISFETs), and High Electron Mobility It can be applied to electronic devices such as transistors (High Electron Mobility Transistors (HEMTs)).

In order to confirm that the p-type dopant contained in the gallium nitride compound semiconductor is activated by the manufacturing method according to the exemplary embodiment of the present application, as shown in FIG. 3, non-conductive Al ₂ O ₃ (sapphire) A gallium nitride based semiconductor layer was formed on the c-plane of the substrate 100 to fabricate a model of a gallium nitride based semiconductor device. Specifically, after growing a thin (˜25 nm) GaN low-growth buffer layer 260 at 530 ° C. using an MOCVD method on the surface of the Al ₂ O ₃ (sapphire) substrate 100, ˜1. 0 μm thick undoped GaN layer 270 and ˜1. Samples of a gallium nitride compound semiconductor device as shown in FIG. 3 were prepared by growing a 0 μm thick Mg-doped gallium nitride based semiconductor layer 280 at 1030 ° C. and 950 ° C., respectively.

More specifically, Al ₂ O ₃ A substrate 100 is set in the chamber of the apparatus for performing MOCVD, and the Al ₂ O ₃ The temperature of the board | substrate 100 was raised to 1100 degreeC, and the surface was thermally etched. Thereafter, while maintaining the temperature at 530 ° C., [Ga (CH ₃ ) ₃ ] (trimethyl gallium) and NH ₃ (ammonia) were injected into the chamber to supply the Al ₂ O _3. A chemical reaction takes place on the surface 110 of the substrate 100 to allow Al ₂ O ₃ A GaN buffer layer 260 having a thickness of ˜25 nm was formed on the c-plane of the substrate 100.

Go on, Al ₂ O ₃ Into the chamber, while raising the temperature of the substrate 100 to 1030 ℃ and held at this temperature Ga (CH _3), Ga (CH ₃₎ over ₃ and the GaN buffer layer 260, and the NH ₃ injection formed in the ₃ and NH ₃ The gallium nitride-based semiconductor layer 270 containing no dopant was formed by the chemical reaction of. The thickness of the gallium nitride based semiconductor layer 270 that does not include the dopant while maintaining the temperature of the substrate at 950 ° C. is ~ 1. At a time point of 0 μm, Mg (C ₅ H ₅ ) ₂ (biscyclopentadienyl magnesium) is injected into the chamber to cause a chemical reaction on the gallium nitride based semiconductor layer 270 containing no dopant. It was. Accordingly, the thickness including Mg as a p-type dopant on the gallium nitride based semiconductor layer 270 that does not include the dopant ˜1. A gallium nitride based semiconductor layer 280 of 0 mu m was formed.

The samples taken out of the chamber were then annealed for 10 minutes at a temperature of 650 ° C. under N ₂ atmosphere. The sample had a hole carrier concentration of 1.9 × 10 ¹⁷ cm ⁻³ and a mobility of ˜11 cm ² / Vs. Carrier properties were measured by a Hall effect measurement system (Ecopia HMS 3000) using nickel / gold (5/15 nm) contacts.

As shown in FIG. 1, a gallium nitride based semiconductor layer 280 containing Mg as a p-type dopant of the sample after the annealing process is bonded to the wiring 700 using indium to form a working electrode. Used as. In addition, a Pt (platinum) sheet was used as the counter electrode 300. Wires were connected to the working electrode, the counter electrode, and the reference electrode, respectively, to be connected to the power source 600. A gallium nitride-based semiconductor including the p-type dopant is contacted with a 0.5 M KOH electrolyte solution (electrolyte) by contacting a sample including the gallium nitride-based semiconductor layer 280 containing the p-type dopant. H ⁺ ions were removed through the formation of H ₂ O at the surface of layer 280.

Specifically, the gallium nitride based semiconductor layer 280 and the counter electrode 300 including a p-type dopant, which is a working electrode, using a typical constant voltage system with a forward voltage in a range of 0 to 10 V in contact with the electrolyte. ) For 4 minutes.

4 is a result of analyzing the hole concentration after activation according to various applied voltages according to an embodiment of the present application. As shown in FIG. 4, it was observed that the applied voltage increased the hole concentration of the p-type gallium nitride based compound semiconductor layer. At all applied voltages, the hole concentration increased more than twice. The greatest increase occurred at an applied voltage of 3 V and hole concentrations from 1.9 x 10 ¹⁷ cm ^-3 to 4.5 x 10 ¹⁷ cm ^-3 About 2.4 times increased. In addition, the surface of the p-type gallium nitride compound semiconductor layer was not affected by the applied voltage of 3V. When the voltage increased above 3 V, the hole concentration decreased again and again increased linearly. When the applied voltage was more than 9 V, the p-GaN surface was dissolved in KOH aqueous solution so that the surface of the p-type gallium nitride compound semiconductor layer became milky white, as shown in FIG. Surface roughness values were measured by atomic force microscopy (AFM), showing about 2.0 nm for standard samples and less than 7 V, and 5.7 nm for samples for 9 V. Gallium nitride is known to dissolve only in boiling KOH aqueous solution, but high voltage excites the P-GaN lattice to dissolve GaN in 0.5 M KOH dilute solution at room temperature. In fact, when a voltage of 20 V or more is applied, most of the p-GaN layer is removed to expose the sapphire substrate. Many variables including the type of solvent, aqueous solution concentration, voltage application time, counter electrode, p-GaN growth conditions, temperature, etc. affect the activation, but the applied voltage is observed to be the most dominant factor here. do.

In this example, the best activation results were obtained at an applied voltage of 3 V. As the applied voltage increases because the stronger electric field breaks more Mg-H bonds and can easily release H atoms, the hole concentration was expected to simply increase. However, in FIG. 4, the hole concentration decreased at an applied voltage of 4-5V. This suggests that in the activation of the p-type dopant by electrochemical potentiometry, a competitive reaction occurs at the working electrode (p-GaN) to suppress the activation of the p-type gallium nitride compound semiconductor. .

Further, gallium oxide was formed on the surface of the electrolyte by reacting the hydroxyl group (OH ⁻ ) with gallium nitride containing a p-type dopant. Gallium oxide attenuated the applied voltage inside the p-type gallium nitride based compound semiconductor layer and inhibited the out-diffusion of H atoms to its surface.

6A shows N ₂ for 10 minutes SIMP (secondary ion mass spectrometry) depth profile of a p-type gallium nitride based layer activated by thermal annealing at 650 ° C. in an atmosphere (Comparative Example), and FIG. 6B is an embodiment of the present application. Is a SIMS depth profile of a p-type gallium nitride based layer activated by electrochemical potentiometry at an applied voltage of 7 V. FIG. As shown in FIGS. 6A and 6B, the analysis by SIMS detected more oxygen atoms when the p-type gallium nitride based compound semiconductor layer was activated using electrochemical electropotential at higher voltage. Hole mobility decreased slightly with increasing the applied voltage but in the range of 9 to 11 cm ² / V s at all voltages.

The SIMS depth profile of the present application shown in FIGS. 6A and 6B shows that the activation method of the p-type dopant by electrochemical potentiometry effectively removes H atoms inside the p-type gallium nitride compound semiconductor layer. To show In FIG. 6A, a comparative example, the p-type gallium nitride based compound semiconductor layer was activated through thermal annealing and had an H concentration of ˜1.7 × 10 ²⁰ cm ⁻³ . In contrast, in Figure 6b H concentration of the sample at 7 V ~ 5.0 x 10 ¹⁹ cm when activated by using an electrochemical electrostatic illegal ^- it was reduced to a ^third. When the p- type gallium nitride-based compound semiconductor layer are activated by using the applied voltage of 3 V, even if the hole concentration exceeds twice, H concentration did not decrease from about 1.7 x 10 ²⁰ cm ^{- 3} was maintained. Although a low applied voltage of 3 V appears to be able to break more Mg-H bonds, it is believed to cause short-range diffusion of H atoms removed from acceptor Mg. These removed H atoms were trapped by dopants of inherent defects such as nitrogen vacancies inside the lattice. High applied voltages such as 7 V are required to release H atoms to the p-GaN surface, and these H atoms react with OH ⁻ at the p-type gallium nitride based compound semiconductor layer surface to form H ₂ O.

In this embodiment, the activation method of the p-type dopant by the electrochemical potentiostatic method effectively improved the hole concentration of the p-type gallium nitride compound semiconductor layer. After the voltage was applied in the KOH electrolyte, the concentration of H atoms decreased and the hole concentration increased more than twice.

A light emitting diode having a layer structure shown in FIG. 2 was produced. First, a sapphire substrate in the form of a wafer was set in a chamber of an apparatus for performing MOCVD, and a buffer layer 120 having a thickness of 25 nm was formed in the same manner as described in Example 1 above.

Next, the temperature of the substrate 100 on which the buffer layer is formed is elevated to 1050 ° C, and SiH is used as a source of silicon (Si) which is Ga (CH ₃ ) ₃ , NH _3, and n-type dopant in the chamber while maintaining the temperature. Injecting ₄ (silane) to cause a chemical reaction on the buffer layer 120, the gallium nitride layer 130 containing silicon as the n-type gallium nitride compound semiconductor layer 130 on the buffer layer 120 Formed. When the thickness of the n-type gallium nitride compound semiconductor layer 130 becomes ˜2 μm, the implantation of SiH ₄ is stopped and [In (CH ₃ ) ₃ ] (trimethylindium) is injected as a source of indium. , an indium gallium nitride (In _x Ga _{1 - x} N, 0 ≦ _x ≦ 0.2) layer was formed on the n-type gallium nitride compound semiconductor layer 130 by chemical reaction as an intermediate layer 140 having a thickness of 0.5 μm. .

Next, while maintaining the temperature of the substrate 100 at 750 ° C., Ga (CH ₃ ) ₃ and NH ₃ are continuously injected into the chamber and [In (CH ₃ ) ₃ ] is intermittently injected to form the intermediate layer 140. ) To allow a chemical reaction to take place. Thus, as the light emitting layer 150, a barrier layer formed of gallium nitride and a well layer formed of indium gallium nitride (In _x Ga _1-x N, 0 ≦ _x ≦ 0.2) are alternately stacked, and the lowermost layer and the uppermost layer are barrier layers. A multilayer quantum well layer (MQW), which is a superlattice device stacked to this end, was formed.

Subsequently, while maintaining the temperature of the substrate 100 at 750 ° C., Ga (CH ₃ ) ₃ and NH _{3 in} the chamber, [Al (CH ₃ ) ₃ ] (trimethyl aluminum) and p− As a source of magnesium as a type dopant, [Mg (C ₅ H ₅ ) ₂ ] (biscyclopentadienyl magnesium) was injected to allow a chemical reaction to occur on the light emitting layer 150. Accordingly, forming a p- type Al _{0 .2} Ga _{0 .8} N (aluminum gallium nitride) layer is p- type gallium nitride-based compound semiconductor layer 200 having a thickness of ~ 20 nm including magnesium as a dopant It became.

Next, the substrate taken out from the chamber was annealed at a temperature of 650 ° C. under N ₂ atmosphere. Subsequently, using the device as shown in FIG. 1, the p-type gallium nitride compound semiconductor layer is bonded to the wiring using indium as a working electrode in the same manner as in Example 1, and used as a working electrode. A predetermined voltage was applied between and to activate the p-type dopant.

After activation of the p-type dopant, the electrode pad 220 is formed by using a laminate including a nickel layer and a gold layer on a part of the surface 210 of the p-type gallium nitride compound semiconductor layer 200. And remove a portion of each of the intermediate layer 140, the light emitting layer 150, and the p-type gallium nitride compound semiconductor layer 200 in the light emitting diode region to form the n-type gallium nitride compound semiconductor layer 130. A laminate including a titanium layer, an aluminum layer, a nickel layer, and a gold layer on the surface 230 of the exposed n-type gallium nitride compound semiconductor layer 130 by exposing a portion of the surface 230 of After forming the electrode pads 240 by using, and then cut each area to separate. Thus, a plurality of light emitting diodes were produced.

The current-voltage characteristic was measured by applying a forward current between the light emitting diodes and the electrode pads 220 and 240. At a current value of 20 mA the operating voltage was between 3. 0 and 3. 3 V.

By the manufacturing method according to an embodiment of the present application, in order to confirm the light extraction improvement according to the activation of the p-type dopant contained in the gallium nitride compound semiconductor, 2 inch Al ₂ O ₃ formed with a gallium nitride based semiconductor layer The substrate (manufacturer: LG Innotek) 100 was annealed at a temperature of 650 ° C. for 10 minutes under N ₂ atmosphere. After the Al ₂ O ₃ 9 boards (100) are cut into 8 pieces per sheet and then p-GaN and Al ₂ O ₃ Indium was applied to the side of the substrate 100. The Al ₂ O ₃ substrate 100 was masked with Maskin Tape (polyethylene) in order to make the area of the substrate in the electrolyte 400 constant.

Next, using the apparatus as shown in Fig. 1, using the gallium nitride compound semiconductor layer 200 containing Mg as a p-type dopant as the working electrode, the masked piece sample was used as a working electrode. Pt (platinum) plate was used as 300). This experiment by the electrochemical potentiometric method by contacting the sample containing the gallium nitride-based semiconductor layer 200 containing the p-type dopant with 0.1 M, 0.3 M, 0.5 M each HCl aqueous solution with a variable molar concentration Was carried out. In order not to put the variable of the experiment, the amount of the aqueous electrolyte solution, the distance and angle of the working electrode and the counter electrode 300 were kept constant.

In order to obtain the optimum conditions, the molar concentration, applied voltage, and application time of HCl electrolyte were set as variables as shown in Table 1 below.

As shown in Table 1, the experiment was performed by dividing the 9-inch wafers into 8 pieces per sheet and performing one cycle with 54 variables. As described above, the p-type dopant activated sample by electrochemical potentiostatic method was subjected to BOE (Buffered Oxide Etchant) treatment after removing the masking tape, removing indium with hydrochloric acid.

For electroluminescence (EL) measurement, as shown in FIGS. 7 and 8, Ni and Au were deposited by stacking 100 Å and 2000 으로서 as p-type electrodes, respectively, in a TCL pattern, and indium was deposited as an n-type electrode. A light emitting diode was produced. EL measurement was performed with the light emitting diode thus manufactured. 9 is a graph of EL measurement results of activation by electrochemical potentiometry with samples that have been thermally anneal activated. As shown in Fig. 9, the graphs on the left are graphs of actual results of EL measurements. In order to easily compare and compare the OP (Optical Power) values of the reference sample which was only activated by thermal annealing, a graph is shown on the right side of the reference unit converted to an arbitrary unit. Referring to FIG. 8, in the present embodiment, light extraction by the electrochemical potentiostatic method is performed by applying a voltage of 4 V for 3 min in a 0.3 M HCl aqueous solution to improve light extraction by about 40% compared with a reference sample. It was confirmed to show.

This example was carried out based on the conditions tested according to Example 3. First, a sapphire substrate (manufacturer: NINEX) was annealed at a temperature of 650 ° C. for 10 min under an N ₂ atmosphere. After that, the p-GaN side and Al ₂ O ₃ Indium was applied to the side of the substrate 100. Then, the substrate was masked with a masking tape (polyethylene) to make the area of the substrate in the electrolyte 400 constant.

Next, using the apparatus as shown in Fig. 1, the p-type gallium nitride compound semiconductor layer was bonded to the wiring using indium and used as a working electrode in the same manner as in Example 3, Pt (platinum) plates were used as electrodes to connect the indium bonded wirings to the power source 600. Using the 0.3 M HCl aqueous solution, the conditions performed in Example 3, the application time was increased by 4 min based on an application time of 3 min at an applied voltage of 4 V, and the present example was increased by 4 min. Was performed. In order not to put the variable of the experiment, the amount of the aqueous electrolyte solution, the distance and angle of the working electrode and the counter electrode 300 were kept constant.

As shown in Table 2, the p-type dopant activated samples were subjected to MESA etching, TCL deposition, metal pad deposition, oxide passivation, and the like. A light emitting diode was manufactured by performing a backgrinding, a scribing fabrication process, and a packaging process made of 3528PLCC 2type as shown in FIG. 10. FIG. 11A is a graph showing the number of chips for the Vf value at 20 mA by probing the entire 2-inch wafer, and FIG. 11B is a graph showing the average Vf value according to the current time of one wafer. Referring to FIG. 11A, the HCl 0.3 M-4 V @ 11 min and @ 15 min graphs are sharper than the reference sample, that is, many chips having the same Vf value appear. In addition, referring to FIG. 11B, it was confirmed that the average Vf value also fell 0.2 V or more at @ 11 min and @ 15 min.

12A to 12F are full probing map data showing Vf at an applied current of 20 mA of a 2-inch wafer using the electrochemical potential activation method according to Example 4 of the present invention. Referring to FIG. 12, in the case of FIGS. 12D and 12E in which the average Vf is more than 0.2 V, unlike the other samples, the Vf increases as the distance from the bottom of the wafer, which is the portion where the current begins to flow during the electrochemical potential activation. I can see that. From this, it can be seen that the electrochemical potential activation proceeds from the current flow portion.

FIG. 13 is a graph showing an average of IV measured values by selecting ten chips having a wavelength of 463 nm (± 1 nm) from each wafer using the electrochemical potential activation method according to Example 4 of the present invention. Referring to FIG. 13, similar to the full probing result in FIG. 12, the average Vf value as well as the Vf value at the same wavelength are about 0.2 at 7 min, 11 min, and 15 min application times based on 20 mA current application. It can be seen that V is reduced.

Therefore, by activating the p-type dopant contained in the gallium nitride compound semiconductor using the electrochemical potentiostatic activation method according to the present embodiment, the hole mobility of the p-type gallium nitride compound semiconductor layer is increased, Since the Vf value can be lowered, power consumption can be reduced when the light emitting device is driven.

As mentioned above, the present invention has been described in detail by way of examples, but the present invention is not limited to the above embodiments, and may be modified in various forms, and within the technical spirit of the present invention, there is a general knowledge in the art. It is obvious that many variations are possible by the possessor.

100: substrate
110: surface of the substrate
120: buffer layer
130: n-type gallium nitride compound semiconductor layer
140: middle layer
150: light emitting layer
200: p-type gallium nitride compound semiconductor layer
210: surface of substrate
220: electrode pad
230: surface of n-type gallium nitride compound semiconductor layer
240: electrode pad
250: laminated body
260 buffer layer
270: gallium nitride-based semiconductor layer containing no dopant
280: gallium nitride based semiconductor layer containing p-type dopant
300: counter electrode
400: electrolyte
500: electrolytic cell
600: power
700: wiring connected to the working electrode
800: wiring connected to the counter electrode

Claims (25)

Forming a gallium nitride compound semiconductor layer comprising a p-type dopant on a substrate;
Contacting the substrate on which the gallium nitride compound semiconductor layer is formed with an electrolyte solution;
Providing a counter electrode in contact with the electrolyte; And
Activating the p-type dopant by applying a voltage between the counter electrode and the gallium nitride based semiconductor layer as a working electrode:
Including,
A method for producing a p-type gallium nitride compound semiconductor.
The method of claim 1,
Wherein the substrate has a resistivity of less than 10 ⁻⁶ Ω · cm.
The method of claim 1,
The substrate is a non-conductive method of producing a p-type gallium nitride based compound semiconductor. The method of claim 1,
The substrate comprises Al ₂ O ₃ , Ga ₂ O ₃ , or SiC, or comprises a GaN thick film, a method for producing a p-type gallium nitride compound semiconductor.
The method of claim 1,
The p-type dopant is selected from the group consisting of Mg, Zn, Cd, Be, Ca, Ba and combinations thereof, a method for producing a p-type gallium nitride compound semiconductor.
The method of claim 1,
The gallium nitride compound semiconductor layer comprising the p-type dopant is formed on the substrate using a vapor-phase deposition method (vapor-phase deposition method), the manufacturing method of the p-type gallium nitride compound semiconductor.
The method of claim 5, wherein
The vapor deposition method is a metal organic chemical vapor deposition (MOCVD) method, molecular beam epitaxy (MBE = Molecular Beam Epitaxy) method or a hydrogen vapor phase epitaxy (HVPE) method, p- A method for producing a gallium nitride compound semiconductor.
The method of claim 1,
The gallium nitride compound semiconductor is gallium nitride, aluminum gallium nitride, indium gallium nitride, or a method for producing a p-type gallium nitride compound semiconductor containing indium aluminum gallium nitride.
The method of claim 1,
The electrolyte solution is provided in the form of a solution or molten salt form, a method for producing a p-type gallium nitride compound semiconductor.
The method of claim 9,
The electrolyte solution is a method for producing a p-type gallium nitride compound semiconductor containing an aqueous solution containing an acidic, neutral or alkaline electrolyte.
The method of claim 9,
The electrolyte solution is a method of producing a p-type gallium nitride compound semiconductor containing at least one molten salt selected from the group consisting of halides of alkali metals and halides of alkaline earth metals.
The method of claim 1,
Further comprising heat-treating the substrate on which the gallium nitride compound semiconductor layer is formed before contacting with the electrolyte solution.
contacting the substrate on which the gallium nitride compound semiconductor layer including the p-type dopant is formed with the electrolyte solution;
Providing a counter electrode in contact with the electrolyte; And
Activating the p-type dopant by applying a voltage between the counter electrode and the gallium nitride based semiconductor layer as a working electrode:
Including,
Activation method of p-type dopant contained in gallium nitride compound semiconductor.
The method of claim 13,
And the substrate is non-conductive, wherein the p-type dopant contained in the gallium nitride compound semiconductor.
The method of claim 13,
The method of activating the p-type dopant contained in the gallium nitride compound semiconductor further comprises heat-treating the substrate on which the gallium nitride compound semiconductor layer is formed before contacting with the electrolyte solution.
The method of claim 13,
The electrolyte solution is provided in the form of a solution or molten salt, the method of activating the p-type dopant contained in the gallium nitride compound semiconductor.
A gallium nitride compound semiconductor device comprising a p-type gallium nitride compound semiconductor manufactured by the method of claim 1.
Board;
An n-type gallium nitride compound semiconductor layer formed on the substrate;
An active layer formed on the n-type gallium nitride compound semiconductor layer; And
A laminate comprising: a gallium nitride compound semiconductor layer comprising a p-type dopant formed on the active layer,
The p-type dopant comprises contacting the laminate with an electrolyte solution; Providing a counter electrode in contact with the electrolyte; Activated by applying a voltage between the counter electrode and a gallium nitride based compound semiconductor layer comprising the p-type dopant as a working electrode,
Light emitting device.
The method of claim 18,
Wherein said substrate has a resistivity of less than 10 ⁻⁶ Ω · cm.
The method of claim 18,
And the substrate is nonconductive.
The method of claim 18,
Wherein the substrate comprises Al ₂ O ₃ , Ga ₂ O ₃ , or SiC.
The method of claim 18,
Wherein said p-type dopant is selected from the group consisting of Mg, Zn, Cd, Be, Ca, Ba and combinations thereof.
The method of claim 18,
Wherein said n-type gallium nitride based compound semiconductor layer, said active layer and said p-type dopant are formed by a vapor deposition method.
The method of claim 23,
The vapor deposition method is a metal organic chemical vapor deposition (MOCVD) method or a hydrogen vapor phase epitaxy (HVPE) method, a light emitting device.
The method of claim 18,
The p-type dopant is contacted with the electrolyte after the heat treatment of the laminate; Providing a counter electrode in contact with the electrolyte; And a voltage applied between the counter electrode and a gallium nitride based compound semiconductor layer comprising the p-type dopant as a working electrode.

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