KR20230061847A - Method for manufacturing GaN thin film by carbon dioxide laser assisted RF sputtering process - Google Patents

Abstract

Disclosed in the present invention is a method for manufacturing a gallium nitride thin film, capable of manufacturing a gallium nitride thin film with excellent crystallinity by a radio frequency (RF) sputtering process in a low temperature by radiating a carbon dioxide laser. The method for manufacturing a gallium nitride thin film includes: a step of arranging a target including gallium nitride and a substrate on which the target is deposited in an RF magnetron sputtering chamber; a second step of injecting an inert gas including argon at partial pressure of 50-70% after decompressing the inside of the chamber by vacuum; and a third step of applying RF electricity of 100-250 W to the target and radiating the carbon dioxide laser to the substrate in a laser duty cycle of 8-12%, thereby performing the RF magnetron sputtering process.

Description

Method for manufacturing GaN thin film by carbon dioxide laser assisted RF sputtering process}

The present invention relates to a method for manufacturing a gallium nitride thin film, and more particularly, to a method for manufacturing a gallium nitride thin film capable of manufacturing a gallium nitride thin film having excellent crystallinity by irradiating a CO ₂ laser and performing an RF sputtering process at a low temperature. will be.

Gallium nitride (GaN), which corresponds to a wide band energy bandgap material, has attracted attention in the field of electronics such as batteries and transistors due to its excellent electrical properties such as a wide bandgap (3.4eV) and high ultraviolet transmittance. In particular, wide energy bandgap semiconductors are particularly promising for power device applications that can withstand high voltages or currents.

In order to deposit such gallium nitride (GaN) in the form of a thin film, the bonding energy of the gallium nitride solid is high, so much energy is required to deposit it on the substrate, and in order to deposit the gallium nitride through a conventional RF sputtering process, the substrate temperature There is a need to supply high thermal energy required for crystallization of the gallium nitride, such as raising about 700 ° C. or additionally performing an annealing process at a high temperature of 600 ° C. to 900 ° C. after the process. Because of this, it is not easy to produce high-quality thin films using conventional physical vapor deposition processes, such as reactive RF sputtering processes or evaporation processes.

Therefore, there is a need to develop a gallium nitride deposition process that is superior to conventional deposition methods that require a lot of energy.

One object of the present invention is to provide a method for producing a gallium nitride thin film, capable of producing a gallium nitride thin film having excellent crystallinity by RF sputtering at a low temperature by irradiating CO ₂ laser.

Another object of the present invention is to provide a gallium nitride thin film manufactured using the above manufacturing method.

As one aspect, the present invention provides a first step of disposing a target containing gallium nitride and a substrate on which the target is to be deposited in a radio frequency (RF) magnetron sputtering chamber; a second step of injecting an inert gas containing argon at a partial pressure of 50% to 70% after depressurizing the inside of the chamber to vacuum; And a third step of applying RF power of 100w to 250w to the target and irradiating the substrate with a CO ₂ laser at a laser duty cycle of 8% to 12% to perform an RF magnetron sputtering process. A thin film manufacturing method is provided.

In one embodiment, the target containing gallium nitride is a gallium nitride ceramic target, and the substrate is characterized in that a sapphire substrate.

In one embodiment, the inert gas is characterized in that it includes argon and nitrogen.

In one embodiment, the CO ₂ laser is characterized in that it has a wavelength of 10,600nm.

In one embodiment, the temperature of the substrate during the process is characterized in that 150 ℃ to 300 ℃.

In one embodiment, the process is characterized in that it is performed for 20 minutes to 40 minutes at an operating pressure of 10 mTorr to 20 mTorr.

As one aspect, the present invention provides a gallium nitride thin film, which is manufactured through the gallium nitride thin film manufacturing method.

In one embodiment, the gallium nitride thin film is characterized in that it has a band gap of 3.2eV to 3.8eV.

In one embodiment, the gallium nitride thin film is characterized in that it grows along the C-plane of the crystal structure.

Preferably, the present invention includes a first step of disposing a target containing gallium nitride and a substrate on which the target is to be deposited in a radio frequency (RF) magnetron sputtering chamber; a second step of injecting an inert gas containing argon at a partial pressure of 60% after depressurizing the inside of the chamber to vacuum; And a third step of applying RF power of 200w to the target and irradiating the substrate with a CO ₂ laser at a laser duty cycle of 11% to perform an RF magnetron sputtering process; do.

According to the gallium nitride thin film manufacturing method of the present invention, during the RF sputtering process, when an infrared laser (IR laser) having excellent heat transfer characteristics is irradiated onto a substrate to supply thermal energy to gallium nitride, which requires a large amount of energy for crystallization, the substrate temperature is raised. A gallium nitride thin film with high crystallinity can be obtained without going through a post-processing process such as heating or applying heat.

1 is a diagram schematically showing an RF magnetic sputtering process of the present invention.
2 is a diagram showing an XRD graph of a gallium nitride thin film according to the partial pressure of argon in an inert gas injected into an RF magnetic sputtering chamber of the present invention.
3 is a diagram showing an XRD graph of a gallium nitride thin film according to RF power applied on a target during the RF magnetic sputtering process of the present invention.
4 is a view showing an XRD graph of a gallium nitride thin film according to a CO ₂ laser duty cycle applied on a substrate during the RF magnetic sputtering process of the present invention.
5 is a view showing a graph of light transmittance and a Tauc plot of a gallium nitride thin film according to a CO ₂ laser duty cycle applied on a substrate during the RF magnetic sputtering process of the present invention.
6 is a graph showing a bandgap graph of a gallium nitride thin film according to a CO ₂ laser duty cycle applied on a substrate during the RF magnetic sputtering process of the present invention.
7 is a view showing SEM images of the surface of a gallium nitride thin film according to the CO ₂ laser duty cycle applied on the substrate during the RF magnetic sputtering process of the present invention.

Hereinafter, embodiments of the present invention will be described in detail. Since the present invention may have various changes and various forms, specific embodiments are illustrated in the drawings and described in detail in the text. However, this is not intended to limit the present invention to a specific form disclosed, and should be understood to include all modifications, equivalents, and substitutes included in the spirit and scope of the present invention.

Terms such as first and second may be used to describe various components, but the components should not be limited by the terms. These terms are only used for the purpose of distinguishing one component from another.

Throughout the specification, when a certain part "includes" or "contains" a certain component, it means that it may further include other components unless otherwise specifically defined. Also, singular expressions used in this specification include plural expressions unless the context clearly indicates otherwise.

Unless defined otherwise, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by a person of ordinary skill in the art to which the present invention belongs, and in this application Unless defined, it is not to be construed in an idealized or overly formal sense.

Hereinafter, the gallium nitride thin film manufacturing method disclosed by the present invention will be described in more detail with reference to the drawings of the present invention.

Gallium nitride has a wide energy band gap of 3.4 eV, high thermal conductivity of 1.3 W/(cm K) (300 K), high lateral breakdown voltage of 10 kV, and high electron mobility of 1000 cm ² /(V s) (300 K). It is a promising semiconductor compound with However, high energy is required to deposit gallium nitride on a substrate due to its wide energy bandgap and high melting temperature of 1600 ° C. To this end, the conventional gallium nitride thin film deposition process requires a lot of equipment maintenance and thin film production. equipment and cost.

A sputtering process conventionally used for depositing the gallium nitride thin film is a process performed in a high vacuum environment inside the chamber. However, if the temperature of the substrate is raised using a heater to transfer thermal energy to the thin film material to be deposited, the high vacuum environment becomes fragile. Should be. This causes a decrease in production yield in the gallium nitride deposition process, and thus, the cost required for the gallium nitride deposition process may increase. In addition, gallium nitride requires a post-processing process such as requiring a high substrate temperature during the process and additional heat treatment after the sputtering process, which may also have an effect on increasing the cost of the process.

Table 1 below lists various conventional processes used to manufacture gallium nitride thin films.

category deposition method Board Substrate temperature (℃) chemical vapor deposition
(CVD) Organometallic Chemical Vapor Deposition C-face sapphire 600 - 1,000 hydride meteorological epitaxy C-face sapphire 600 - 1,045 physical vapor deposition
(PVD) pulsed laser deposition C-face sapphire 550 - 750 Molecular Line Epitaxy C-face sapphire 650 - 850 RF magnetron
sputtering liquid Ga target Quartz, C-face sapphire 800 - 860 GaAs target quartz 600 - 850 GaN target glass 800

Referring to Table 1, it can be seen that a very high substrate temperature of 800° C. or higher is generally required to grow a gallium nitride thin film using a conventional chemical or physical vapor deposition process.

Among physical vapor deposition processes for growing a gallium nitride thin film, a magnetron RF sputtering process is the most representative. During the sputtering process, a method of heating a substrate is widely used to provide sufficient energy for the growth of a gallium nitride thin film, but high thermal energy cannot be transferred to the thin film in a vacuum chamber used in the sputtering process. This is because it is very difficult to maintain a high vacuum state at high temperatures. As a result, it is not possible to grow a high-quality thin film at a high temperature through the general deposition method described in Table 1 above.

To this end, in the present invention, instead of directly heating the substrate, a method of supplying energy necessary for the growth of gallium nitride using CO ₂ laser irradiation is used.

1 is a diagram schematically showing an RF magnetic sputtering process of the present invention.

Referring to FIG. 1, the present invention includes a first step of arranging a target containing gallium nitride and a substrate on which the target is to be deposited in a radio frequency (RF) magnetron sputtering chamber; a second step of injecting an inert gas containing argon at a partial pressure of 50% to 70% after depressurizing the inside of the chamber to vacuum; And a third step of applying RF power of 100w to 250w to the target and irradiating the substrate with a CO ₂ laser at a laser duty cycle of 8% to 12% to perform an RF magnetron sputtering process. A thin film manufacturing method is provided.

In the present invention, during the RF magnetron sputtering process of a target including gallium nitride, a CO ₂ laser in the infrared region is irradiated through a ZnSe viewport located on the side of an RF magnetron sputtering chamber to supply energy to the substrate, thereby supplying energy to nitride with improved crystallinity. A method for producing a gallium thin film. In this case, preferably, the target containing gallium nitride may be a gallium nitride ceramic target, and the substrate may be a sapphire substrate.

The CO ₂ laser in the infrared region has excellent heat transfer characteristics during a sputtering process, and through this, it is possible to improve characteristics of a gallium nitride thin film manufactured by transferring thermal energy to a substrate. At this time, the CO ₂ laser may have a wavelength of 10,600 nm, and the CO ₂ laser of 10,600 nm, which is a wavelength converted into photon energy of 0.12 eV, is transferred to a thin film during RF sputtering and converted from optical energy to thermal energy to generate thermal energy. can be transferred to the substrate. Gallium nitride, which requires high thermal energy for crystallization, can be deposited on the substrate at a relatively low temperature by irradiation of the laser in the infrared range. In the present invention, when the process is performed, the temperature of the substrate may be 150 °C to 300 °C, preferably 200 °C.

This is a much lower value than the temperature of 600 ° C. or higher in the conventional sputtering method shown in [Table 1], and additionally, as in the conventional method, only the substrate temperature is raised or gallium nitride obtained through post-annealing and When comparing crystallinity, a gallium nitride thin film formed using CO ₂ laser irradiation may have higher crystallinity than a gallium nitride thin film formed using a conventional sputtering method.

In the gallium nitride manufacturing process of the present invention, the inert gas is characterized in that it includes argon and nitrogen. Crystallinity of the gallium nitride thin film may be improved by adjusting the partial pressure of argon in the inert gas, and the partial pressure of argon may be 50% to 70%, preferably 60%.

In addition, in the gallium nitride manufacturing process of the present invention, as the RF power applied to the target, RF power of 100w to 250w may be used, and preferably, power of 200w may be used. Similar to the partial pressure of argon, when an appropriate RF power is used, the crystallinity of the resulting gallium nitride thin film can be improved.

Additionally, in the gallium nitride manufacturing process of the present invention, when irradiating the laser duty cycle of the CO ₂ laser at 8% to 12%, preferably 11%, like the partial pressure of argon and the RF power, generated The crystallinity of the gallium nitride thin film can be improved.

The specific effects of the three process conditions of argon partial pressure, RF power, and CO ₂ laser duty cycle described above on the formed gallium nitride thin film are described in the following evaluation examples.

In addition to this, the process may be performed for 20 minutes to 40 minutes at an operating pressure of 10 mTorr to 20 mTorr.

Finally, the present invention, most preferably, a first step of disposing a gallium nitride silicon target and a sapphire substrate on which the target is to be deposited in a radio frequency (RF) magnetron sputtering chamber; a second step of injecting an inert gas containing argon at a partial pressure of 60% and nitrogen containing the remainder after depressurizing the inside of the chamber to vacuum; And a third step of applying RF power of 200w to the target and irradiating the substrate with a CO ₂ laser at a laser duty cycle of 11% to perform an RF magnetron sputtering process; do.

The gallium nitride thin film, which is manufactured through the gallium nitride thin film manufacturing method, may have a band gap of 3.2 eV to 3.8 eV, which is a wide band gap value of 3.4 eV, which is the band gap of a conventional gallium nitride thin film that is electrically excellent. is a value similar to Therefore, since the gallium nitride thin film formed by the manufacturing method of the present invention also has excellent electrical properties, it can be used in the field where conventional gallium nitride thin films are used. In addition to this, the gallium nitride thin film formed by the manufacturing method of the present invention can be grown along the C-plane of the crystal structure.

Hereinafter, various embodiments and evaluation examples of the present invention will be described in detail. However, the following examples are merely some examples of the present invention, and the present invention should not be construed as being limited to the following examples.

<Example>

1. Preparation of gallium nitride thin film

The gallium nitride thin film of the present invention was fabricated on a sapphire substrate by performing a gallium nitride ceramic target (purity of 99.99%) and a CO ₂ laser-assisted RF sputtering process at a base pressure of 10 ⁻⁶ mTorr.

Pre-sputtering was performed on a gallium nitride ceramic target (purity of 99.9%) and a sapphire (C-plane) substrate located in an RF sputtering chamber to clean the target and substrate, and acetone, ethanol, and deionized water were used to wash the target for 10 minutes. and sonic cleaning the substrate. During RF sputtering, a CO ₂ laser with a wavelength of 10,600 nm was used to transmit photon energy by illuminating the substrate through a ZnSe single crystal viewport located on the side of the RF sputtering chamber. At this time, the operating temperature and pressure during the RF sputtering process were set to 200° C. and 15 mTorr, respectively, and during the RF sputtering process using a CO ₂ laser, the RF power was 200 W, the argon partial pressure was 60%, and the laser duty was 11%.

<Evaluation example>

Evaluation Example 1: partial pressure of argon

2 is a diagram showing an XRD graph of a gallium nitride thin film according to the partial pressure of argon in an inert gas injected into an RF magnetic sputtering chamber of the present invention.

In FIG. 2, the characteristics of the gallium nitride thin film produced according to the partial pressure of argon during the manufacturing process of the present invention were analyzed through XRD graphs. For the above analysis, the RF sputtering process was set to a substrate temperature of 200 ° C, RF power of 200 W, and process pressure of 15 mtorr, and the partial pressures of argon in the inert gas were set to 20%, 40%, 60% and 80% of the present invention. Examples were carried out.

Referring to FIG. 2, the diffraction peak at the (10-10) crystal plane of the RF-sputtered gallium nitride thin film was found to be the highest when the partial pressure of argon was 60%. The (10-10) crystal plane is a plane with the lowest surface energy in gallium nitride having a wurtzite structure, and is a non-polar plane that mainly grows at low temperatures when crystals are formed. This means that the crystallization of gallium nitride proceeded easily.

In addition, it is known that the partial pressure of the inert gas depends on the plasma density, and the argon partial pressure in the plasma increases as the argon partial pressure increases, since the quality of the plasma is affected by the discharge current. can Therefore, it means that optimizing the argon partial pressure during the RF sputtering process is an important factor in improving the crystallinity of the gallium nitride thin film.

Evaluation Example 2: RF power applied on the target

3 is a diagram showing an XRD graph of a gallium nitride thin film according to RF power applied on a target during the RF magnetic sputtering process of the present invention.

In FIG. 3, the characteristics of the gallium nitride thin film produced according to the RF power during the manufacturing process of the present invention were analyzed through XRD graphs. For the above analysis, the RF sputtering process was set to a substrate temperature of 200 ° C, an argon partial pressure of 60%, and a process pressure of 15 mtorr, and the RF power was set to 100 w, 150 w, and 200 w to perform an embodiment of the present invention.

Referring to FIG. 3, the diffraction peak at the (10-10) crystal plane of the RF sputtered gallium nitride thin film was found to be the highest when the RF power was 200w. As can be seen in FIG. 3, as the applied RF power increases, the intensity of the reflection peak on the (10-10) crystal plane of the formed gallium nitride thin film increases. This means that high RF power is effective in forming the gallium nitride thin film through the RF sputtering process. The high RF power is converted into argon plasma having high kinetic energy during RF sputtering, which causes high kinetic energy to be supplied to the gallium nitride thin film.

Evaluation Example 3: CO ₂ laser duty cycle

4 is a view showing an XRD graph of a gallium nitride thin film according to a CO ₂ laser duty cycle applied on a substrate during the RF magnetic sputtering process of the present invention.

In FIG. 4, the characteristics of the gallium nitride thin film produced according to the CO ₂ laser duty cycle during the manufacturing process of the present invention were analyzed through XRD graphs. For the above analysis, the RF sputtering process was set at a substrate temperature of 200 °C, RF power of 200 W, argon partial pressure of 60%, and process pressure of 15 mtorr, and the CO ₂ laser duty cycle with a wavelength of 10,600 nm was set to 0% to have a photon energy of 0.12 eV. , 5%, 7%, 9%, 11%, and 13% to perform an embodiment of the present invention.

Referring to FIG. 4, when comparing XRD data of (10-10) crystal planes at 5% and 7% CO ₂ laser duty cycles with samples not irradiated with laser, as the laser duty cycle increases (10- It can be seen that the crystal plane data of 10) has been improved. At a CO ₂ laser duty cycle of 5%, the diffraction peak of the (10-10) crystal plane was higher than that of the sample without laser irradiation, and the CO ₂ laser duty cycle as well as the (10-10) plane of the gallium nitride thin film. The XRD data of the (0002) crystal plane at 7%, 9%, and 11% were compared, and it was confirmed that the (0002) crystal plane and the (10-11) crystal plane grew from the CO ₂ laser duty cycle of 7%. In addition, (0002), which has the highest nucleation energy at a laser duty cycle of 11%, showed a diffraction peak about 60 times higher than that of the sample with a CO2 laser duty cycle of 7%. This means that the wavelength of CO ₂ laser efficiently provided thermal energy. However, at a CO ₂ laser duty cycle of 13%, the XRD data value was very low as the thin film was damaged.

Among the gallium nitride planes, it was confirmed that the surface energy of the (0002) plane was significantly higher than that of the other planes (1010) and (1011). This means that the c-plane of the gallium nitride thin film requires the highest non-uniform nucleation energy. Referring to the XRD graph of FIG. 4, the energy given to the gallium nitride thin film in the CO ₂ laser-assisted RF sputtering process causes crystal growth along the C-plane (0002) under a CO ₂ laser duty cycle of 9% to 11%. It can be seen that this is sufficient to promote and that the gallium nitride thin film has started to grow along the C-plane (0002).

In addition, the XRD profiles of the CO ₂ laser-assisted RF sputtered gallium nitride thin film formed by a laser duty cycle of 13% were similar to those of the unbonded gallium nitride thin film and the clean sapphire substrate, respectively. This means that when the gallium nitride thin film is formed by the 13% laser duty cycle, the thin film is damaged by exceeding the laser induced damage threshold (LIDT).

(1)

(One)

In Equation (1), γ _vf is the surface energy of the nucleus-substrate, G _v is the Gibbs free energy per unit volume of the solid phase, and θ is the contact angle at the thin-film-substrate interface. In the case of an unattached gallium nitride thin film, the contact angle θ is 180°. In general, since gallium nitride has a wurtzite structure, the surface energy (γ _vf ) of the nucleus-substrate depends on the plane direction. The surface energy (γ _vf ) values of the nucleus-substrate of GaN semiconductor having a general wurtzite structure are shown in Table 2 below. The nuclear-substrate surface energy (γ _vf ) values of (10-10), (10-11), and (0002) planes of the gallium nitride thin film formed through the present invention are 1.40 J/m ² and 1.76 J/m, respectively. m ² , and 2.64 J/m ² .

GaN face (0001) (1120) (1011) (1010) Surface energy (J/m ² ) 2.64 1.53 1.76 1.40

5 is a view showing a graph of light transmittance and a Tauc plot of a gallium nitride thin film according to a CO ₂ laser duty cycle applied on a substrate during the RF magnetic sputtering process of the present invention.

Similar to FIG. 4, in FIG. 5, the characteristics of the gallium nitride thin film produced according to the CO ₂ laser duty cycle during the manufacturing process of the present invention were analyzed through a light transmittance graph and a Tauc plot graph. For the above analysis, the RF sputtering process was set at a substrate temperature of 200 °C, RF power of 200 W, argon partial pressure of 60%, and process pressure of 15 mtorr, and the CO ₂ laser duty cycle with a wavelength of 10,600 nm was set to 0% to have a photon energy of 0.12 eV. , 5%, 7%, 9%, 11%, and 13% to perform an embodiment of the present invention.

Referring to FIG. 5, light transmission of CO ₂ laser-assisted RF sputtering gallium nitride thin films fabricated with laser duty cycles of 0%, 5%, 7%, 9%, 11%, and 13% in the wavelength range of 200 nm to 800 nm. spectrum, and the transmittance was measured using a UV-vis spectrometer by simulating the gallium nitride thin film on a Tauc plot, and then (ahv) ² vs.hv curve was inserted into the light transmission spectrum graph.

(2)

(2)

In Formula (2), a is the absorption coefficient, E _g is the optical band gap of the gallium nitride thin film, hv is the photon energy, and A is a constant.

Referring to FIG. 5, it can be seen that the light transmission wavelength in the range of 300 nm to 400 nm decreases as the laser duty cycle increases. The wavelength range from 300 nm to 400 nm corresponds to a band gap range of 3.4 eV, and the band gap energy of wurtzite gallium nitride is 3.4 eV. This indicates that crystal growth of wurtzite gallium nitride is enhanced with increasing laser duty cycle.

6 is a graph showing a bandgap graph of a gallium nitride thin film according to a CO ₂ laser duty cycle applied on a substrate during the RF magnetic sputtering process of the present invention.

Similar to FIG. 4, in FIG. 6, the characteristics of the gallium nitride thin film produced according to the CO ₂ laser duty cycle during the manufacturing process of the present invention were analyzed through a bandgap graph. For the above analysis, the RF sputtering process was set at a substrate temperature of 200 °C, RF power of 200 W, argon partial pressure of 60%, and process pressure of 15 mtorr, and the CO ₂ laser duty cycle with a wavelength of 10,600 nm was set to 0% to have a photon energy of 0.12 eV. , 5%, 7%, 9%, 11%, and 13% to perform an embodiment of the present invention.

Referring to FIG. 6, it can be seen that the band gap decreases as the CO ₂ laser duty cycle increases. When the laser duty cycle is 11%, the energy band gap of the CO ₂ laser-assisted RF sputtering gallium nitride thin film is It was measured as 3.32 eV, which is similar to the band gap of 3.4 eV of the conventionally disclosed gallium nitride thin film.

On the other hand, a laser duty cycle higher than 13% excessively increases the energy density of the gallium nitride thin film, which may cause peeling and re-evaporation of the gallium nitride thin film deposited on the sapphire substrate. Therefore, it means that there exists a value of the CO ₂ laser duty cycle at which the optimized photon energy of the CO ₂ laser improves the crystalline properties of the gallium nitride thin film along the C-plane. Referring to FIG. 6, CO ₂ laser duty cycles of 5%, 7%, 9%, and 11%, which have a band gap similar to that of the conventional gallium nitride thin film, show excellent values, of which 11% It can be seen that the CO ₂ laser duty cycle is the most suitable value for the gallium nitride thin film manufacturing process of the present invention.

7 is a view showing SEM images of the surface of a gallium nitride thin film according to the CO ₂ laser duty cycle applied on the substrate during the RF magnetic sputtering process of the present invention.

As in FIG. 4, in FIG. 7, the characteristics of the gallium nitride thin film generated according to the CO ₂ laser duty cycle during the manufacturing process of the present invention, the field emission scanning electron microscope (FE-SEM) image of the surface of the thin film analyzed through For the above analysis, the RF sputtering process was set at a substrate temperature of 200 °C, RF power of 200 W, argon partial pressure of 60%, and process pressure of 15 mtorr, and the CO ₂ laser duty cycle with a wavelength of 10,600 nm was set to 0% to have a photon energy of 0.12 eV. , 5%, 7%, 9%, 11%, and 13% to perform an embodiment of the present invention.

Referring to FIG. 7, in the case of the sample without laser irradiation and the example of the CO ₂ laser duty cycle of 5%, gallium nitride was irregularly deposited in the form of particulates on the substrate, and _CO 2 from the laser duty cycle of 7% CO ₂ It can be seen that the gallium nitride crystals were uniformly distributed until the laser duty cycle of 11%, and the size of the gallium nitride crystals gradually increased. Through this, it can be confirmed that the CO ₂ laser duty cycle significantly affects the surface morphology of the gallium nitride thin film during the manufacturing process of the gallium nitride thin film according to the present invention.

In addition, a partially damaged surface was observed in the CO ₂ laser-assisted RF sputtering gallium nitride thin film fabricated with a high laser duty cycle of 13%, indicating that a high laser duty cycle value may rather damage the formed gallium nitride thin film. show what

Although the above has been described with reference to preferred embodiments of the present invention, those skilled in the art can variously modify and change the present invention without departing from the spirit and scope of the present invention described in the claims below. You will understand that you can.

Claims (9)

A first step of disposing a target containing gallium nitride and a substrate on which the target is to be deposited in a radio frequency (RF) magnetron sputtering chamber;
a second step of injecting an inert gas containing argon at a partial pressure of 50% to 70% after depressurizing the inside of the chamber to vacuum; and
A third step of applying RF power of 100w to 250w to the target and irradiating the substrate with a CO ₂ laser at a laser duty cycle of 8% to 12% to perform an RF magnetron sputtering process;
A method for producing a gallium nitride thin film.
According to claim 1,
The target containing gallium nitride is a gallium nitride ceramic target, and the substrate is a sapphire substrate.
A method for producing a gallium nitride thin film.
According to claim 1,
The inert gas includes argon and nitrogen,
A method for producing a gallium nitride thin film.
According to claim 1,
The CO ₂ laser has a wavelength of 10,600 nm,
A method for producing a gallium nitride thin film.
According to claim 1,
When the process proceeds, the temperature of the substrate is 150 ° C to 300 ° C,
A method for producing a gallium nitride thin film.
According to claim 1,
The process is carried out for 20 to 40 minutes at an operating pressure of 10 mTorr to 20 mTorr,
A method for producing a gallium nitride thin film.
Manufactured through the gallium nitride thin film manufacturing method of claim 1,
Gallium nitride thin film.
According to claim 7,
The gallium nitride thin film has a band gap of 3.2 eV to 3.8 eV,
Gallium nitride thin film.
According to claim 7,
The gallium nitride thin film is grown along the C-plane of the crystal structure,
A method for producing a gallium nitride thin film.

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