KR101301197B1 - Method for manufacturing thin film of single crystal sapphire for led chip substrate and led chip thereby - Google Patents

Abstract

PURPOSE: A method for manufacturing a thin film of single crystal sapphire for an LED chip substrate and the LED chip thereby are provided to reduce production costs by minimizing loss due to a cutting process. CONSTITUTION: Aluminum of a thickness of 100-10000 nm is deposited on one surface of a quartz glass substrate (3). The deposited aluminum is locally heated. Oxygen (5) is in contact with the heated aluminum. Single crystal sapphire is formed by changing aluminum through an oxidation reaction. The single crystal sapphire formed by the oxidation reaction is slowly cooled.

Description

Method for manufacturing thin film of single crystal sapphire for LED chip substrate and LED chip thereby

The present invention relates to a sapphire single crystal thin film for LED chip substrate, and more particularly, to manufacture a sapphire single crystal thin film for LED chip substrate to form a sapphire single crystal thin film in a simplified process of depositing and directly oxidizing aluminum on a quartz glass substrate. It relates to a method and an LED chip manufactured therefrom.

Recently, LED has expanded its use to back light units such as mobile phones, monitors, and televisions, and is expected to be extended to high-brightness lighting such as next-generation lighting and automotive headlights. Is gradually expanding.

The core technology of LED manufacturing is the formation of gallium nitride (GaN) epilayer of multilayer thin film manufactured by MOCVD (Metalorganic Chemical Vapor Deposition) process, but GaN single crystal is optimally used as LED chip substrate for GaN epilayer formation. Single crystals are very difficult and expensive to grow, which makes them extremely limited for use as LED chip substrates.Since, another LED chip substrate material, silicon carbide (SiC) has relatively small GaN and lattice mismatch and other physical properties. Although a good material for LED chip substrates, it is difficult and expensive to economically manufacture single crystals of size for industrial applications due to the difficult crystal growth method.

Sapphire is used as another LED chip substrate material for forming a GaN epilayer in LED chip manufacturing.

Sapphire is a single crystal of corundum, which is a crystalline form of aluminum oxide or alumina, and sapphire gemstones produced in nature may include iron (Fe), titanium (Ti), vanadium (V), and the like as impurities.

Sapphire has a very high melting point of 2045 ℃, density is 3.98 g / cc, Mohs hardness is 9.0, thermal expansion coefficient is 7 ~ 8x10 ^-6 K, thermal conductivity is 0.272 J / cmK, specific resistance is> 10 ¹⁴ Ωm. It has excellent characteristics as a substrate, and can control the surface crystallinity of sapphire substrate to the extent that GaN can be grown, and there are few materials to replace sapphire industrially.

Currently, methods of growing sapphire single crystals for LED chip substrates include Kyropoulus method, VHGF (Vertical-Horizontal Gradient Freezing) method, Controlled Heat Extraction System (CHES) method, Czochralski method, etc. There is this.

Among them, the Chiropolus method was developed by Monocrystal Inc. in Russia and is the most widely used internationally. The VHGF method is a proprietary technology owned by Sapphire Technology Co., Ltd. in Korea. Exchange Method) It is a kind of growth method.

In 2007, the US Advanced Renewable Energy Company (ARC Energy) developed a method called CHES, which can grow near-net shaped sapphire for 6˝, 8˝, and 10˝ wafers in the c-axis direction. There is a tendency to employ a lot in the new entry market.

In addition, C-axis growth by the Czochralski method has grown more than 6 ”of single crystals at the Fukuda Crystal Research Institute in Kyushu University, Japan, but it is still under study, and it is difficult to suppress the formation of defects.

In order to use a sapphire wafer as a substrate for epitaxial deposition, a single crystal structure aligned in one axial direction with high purity, surface flatness, constant thickness, and crystallography is required.

High purity of 99.999% or more in the existing manufacturing methods including the Czochralski method, Kyropolous method, VHGF (Vertical Horizontal Gradient Freezing), HEM method (Heat Exchange Method) or modified HEM method The raw material purified by the crystallization method requires a high production temperature of 2050 ° C or higher, which is higher than the melting point of aluminum oxide (alumina) in a specific crystal growth furnace according to the crystal growth method for several days to two weeks or longer. Expensive crucibles such as iridium (Ir) and molybdenum (Mo) are necessary to store melt for a long time, and the crucible deterioration is prevented at the interface between liquid alumina and crucible as much as possible. And extracting from the ingot into a mass of cylindrical shape in a specific crystallographic direction (core-dr). After illing or processing, there is a problem of cutting and polishing while minimizing kerf-loss in the form of a wafer.

In Korean Patent Publication No. 10-0428699, seed crystals are placed inside a crucible, charged with a crystalline material, and then melted at a high temperature, and the temperature is gradually increased in the horizontal and vertical directions with respect to the portion where the seed crystals are located. By slowly descending to grow crystals, there is provided a method for growing rod-shaped crystals longer in length than the length of the cross section.

However, although the patented method improves the existing manufacturing method, the problems due to the purification of crystalline material, the energy consumption due to high temperature melting, the need of the crucible and the loss due to the cutting processing of the manufactured crystal are still not solved. not.

Meanwhile, LED chips are manufactured by depositing compounds such as GaN and InGaN in the form of multilayer thin films on the surface of a sapphire substrate. In order to release heat generated during the operation of the LED chip, the thickness of the sapphire substrate needs to be minimized. After depositing a compound multilayer thin film such as GaN for sapphire, the sapphire substrate may be removed or the thickness thereof may be minimized, but the sapphire substrate may be minimized to minimize deformation and lattice mismatches such as warpage of the sapphire substrate at the epi deposition temperature. There is also a limit to minimizing the thickness.

Therefore, if a sapphire single crystal thin film required for epi deposition such as GaN can be formed, a single crystal growth process that takes a long time and a lot of energy, a process of cutting and polishing a bulk single crystal into wafer form, and an LED chip device are manufactured. After the heat dissipation can be omitted or simplified to reduce the sapphire thickness.

The sapphire thin film can be manufactured by various processes, but for epi deposition, it has to be grown in the form of single crystal instead of polycrystal, but the method of forming sapphire single crystal thin film on the substrate for LED device manufacturing Has not been reported.

The present invention, in order to solve the problems of the prior art as described above, unlike the method of growing a sapphire single crystal in the form of agglomerate, which is a conventional manufacturing method and cutting it to produce a wafer form, using a deposition and oxidation method of aluminum It is an object of the present invention to provide a method for manufacturing a sapphire single crystal thin film for an LED chip substrate, which is economical with a simplified process and can form a thin sapphire single crystal thin film capable of epi deposition.

In order to achieve the above object, the present invention comprises the steps of (A) depositing aluminum on one surface of the quartz glass substrate; (B) In the chamber for converting the aluminum into sapphire, locally heated the deposited aluminum so that the portion heated by the heating device is a straight line, and the undeposited underside of the quartz glass substrate on which the aluminum is deposited Cooling the portion to be cooled in a straight line while contacting oxygen with the heated aluminum to convert the aluminum by an oxidation reaction to form a sapphire single crystal; And (C) continuously moving the aluminum-deposited quartz glass substrate in the longitudinal direction or continuously moving the heating device in the longitudinal direction of the aluminum-deposited quartz glass substrate. It provides a method for producing a thin film.

By means of the above solution, the present invention is a separate multi-step process of high-purity purification of alumina raw material, the melting of the entire alumina in the crucible, the growth of sapphire single crystal, cutting of the sapphire ingot and polishing of the sapphire wafer, which is a conventional manufacturing method Compared with the phosphorus, the manufacturing process is simplified, no purification process is required, and deterioration of the crucible due to the reaction of the crucible surface with the alumina melt and inflow of impurities are essentially excluded, thereby obtaining a high purity uniform sapphire single crystal thin film.

In addition, the present invention does not require an expensive crucible, energy is reduced by shortening the time for forming the sapphire single crystal thin film, and the loss in the cutting process is minimized, thereby reducing the production cost.

In addition, the present invention can manufacture the LED chip substrate without limitation of the width and length, when forming the epi layer on the LED chip substrate at a high temperature of 500 ~ 1100 ℃ in the MOCVD process of LED manufacturing, the LED chip of the present invention The substrate is excellent in mechanical strength by the quartz glass substrate even at the high temperature, thereby reducing warpage and defects in the epi layer, thereby increasing the yield of the LED chip, and making the price cheaper than the conventional sapphire substrate.

In addition, the thickness of the sapphire single crystal thin film can be minimized, thereby providing an effect of easily dissipating heat generated during the operation of the LED chip.

1A is a conceptual diagram of a method of manufacturing a sapphire single crystal thin film for an LED chip substrate by oxidation using an infrared heating device according to the present invention;
1B is a conceptual diagram of a method of manufacturing a sapphire single crystal thin film for an LED chip substrate by oxidation using a laser heating device according to the present invention;
2 is a conceptual diagram in which a sapphire single crystal according to the present invention is formed,
3 is a photograph showing that aluminum is converted into sapphire according to before and after the oxidation reaction according to the present invention,
4 is a scanning electron microscope microstructure photograph and EDS (Energy Dispersive Spectroscopy) analysis data showing an aluminum region and an sapphire single crystal region in which oxidation is not completed according to the present invention.
5 is a planar and cross-sectional scanning electron micrograph of a sapphire single crystal thin film according to the present invention,
6 is X-ray diffraction analysis results and EDS data of the sapphire single crystal thin film according to the present invention.

Hereinafter, the manufacturing method of the sapphire single crystal thin film for LED chip substrate of this invention is demonstrated in detail.

(A) High purity aluminum is deposited on one surface of a quartz glass substrate.

The quartz glass substrate has better heat resistance and chemical stability and lower production cost than the sapphire wafer according to the conventional manufacturing method.

In the present invention, the composition, shape, size, thickness, and length of the quartz glass substrate are not particularly limited, and may be configured by connecting the manufacturing process of the quartz glass substrate and the deposition process of aluminum.

Aluminum is a metal, which has a face-centered cubic structure (FCC) in which aluminum atoms are close-packed, and grains in the form of single crystals in which the atoms have a spatially regular arrangement are usually several μm to It is polycrystalline in size of several tens of micrometers.

The deposition method of the aluminum may be a known method, more preferably by physical deposition of sputtering or thermal evaporation.

The deposition of aluminum on the quartz glass substrate is performed in a chamber, wherein the chamber is a high vacuum to minimize the amount of residual oxygen or a pressure in the chamber is injected by injecting argon inert gas containing hydrogen to maintain a reducing atmosphere. Is 0 to 1 atm.

The deposition thickness of the aluminum is preferably in the range of 100 ~ 10000 nm in order to be used as a sapphire single crystal thin film for the LED chip substrate. If the deposition thickness is less than 100 nm, the crystallinity of the formed sapphire is reduced and the regular arrangement of atoms is reduced. GaN epitaxial growth is difficult due to high deviation from the perfect single crystal structure, and if it exceeds 10000 nm, the heat radiation of the GaN epitaxial layer formed on the sapphire single crystal thin film is not smooth.

(B) a portion of the chamber where the heated aluminum is locally heated using an infrared or laser heating device so that the heated portion becomes a straight line in a narrow region, and the undeposited bottom surface of the deposited quartz glass substrate is cooled. While cooling to be a straight line, oxygen is brought into contact with the heated aluminum to convert the deposited aluminum into a sapphire single crystal by an oxidation reaction.

When aluminum oxidizes with oxygen, it becomes aluminum oxide, which is called alumina, which is called alumina. Alumina has a unit cell of close-packed hexagonal lattices.

The crystalline material of alumina is called corundum, and if the single crystal of corundum contains chromium (Cr) as an impurity, red gemstone is ruby, other iron (Fe), titanium (Ti), vanadium (V) and so on are called sapphire.

Sapphire expresses various colors such as blue, green, yellow, purple, and pink depending on the type and content of impurities, but as a jewel, sapphire generally refers to a blue single crystal in which Fe and Ti are present as impurities. Although color and shade are different depending on the element type and concentration of impurities, corundum that is minimized as much as possible in industrial applications is called sapphire.

Sapphire has excellent transparency, high strength, abrasion resistance, and thermal stability at high temperatures, so it is used for expensive watch windows, missile radomes, or as a window for high temperature chambers in the semiconductor industry. In addition, due to the structural thermal stability and the lattice constant suitable for epitaxial growth, it was widely used as a research substrate for thin film growth, but the demand increased due to the rapid expansion of the LED industry.

When the deposited aluminum is heated to a high temperature of 500 ~ 2100 ℃ by the infrared or laser heating device, the aluminum is instantaneously melted into a high-temperature fluidized bed, and in contact with oxygen directly into sapphire as aluminum oxide by oxidation reaction The oxidation reaction is diffused while the oxygen diffuses along the solid-liquid interface formed by the hot fluidized aluminum.

In this process, the deposited aluminum is heated and the undeposited bottom surface of the deposited quartz glass substrate is cooled, that is, a temperature gradient is provided between the deposited aluminum and the quartz glass substrate, The sapphire formed is grown in the form of a single crystal rather than polycrystalline.

The temperature gradient is a temperature difference according to a distance. When the temperature gradient is small, the growth direction of the particles becomes random and polycrystalline is formed. However, when the temperature gradient is large, the single crystal is formed by controlling the growth direction of the particles. You can.

In the temperature gradient of the present invention, the temperature of the heated portion of the deposited aluminum is preferably in the range of 500 to 2100 ° C, and the temperature of the cooling portion of the quartz glass substrate is in the range of -195.8 to 400.0 ° C.

When the temperature of the heating portion is less than 500 ℃, the oxidation reaction of aluminum is performed in proportion to the temperature, the temperature of aluminum is too low than the melting temperature of aluminum, the oxidation reaction is slow, and oxygen reacts with aluminum to form sapphire The reaction proceeds from the surface of aluminum. Once the sapphire film is formed on the surface of aluminum, oxygen sapphire film is difficult to diffuse and bond with the underlying aluminum atoms. The reaction is unlikely to occur.

If the temperature of the heating portion exceeds 2100 ℃ energy consumption is not preferable in terms of economics.

In the quartz glass substrate, in order to form a temperature gradient suitable for sapphire single crystal growth on a bottom plane on which an aluminum metal thin film is not deposited, by forming a cooling part at a predetermined distance from the heating part and parallel to the heating part. In the deposited aluminum metal thin film surface, a high temperature gradient may be formed between a heating portion having a straight shape and an adjacent portion which is not heated, and the deposition is performed from the bottom surface of the quartz glass substrate in the thickness direction of the deposited aluminum metal thin film. As the temperature gradient can be formed in the surface direction of the aluminum metal thin film, single crystal growth starts from the deposited aluminum metal thin film portion in contact with the surface of the quartz glass substrate. At the same time, the heating apparatus is moved at a constant speed or the quartz glass substrate on which aluminum metal is deposited is moved at a constant speed to grow a sapphire thin film single crystal in the form of a plate.

If the cooling temperature of the bottom surface of the quartz glass substrate is less than −195.8 ° C., the increase of the single crystal growth effect due to cooling is insignificant and the economical efficiency is lowered. If it exceeds 400.0 ° C., the single crystal growth is difficult, which is not preferable.

In addition, by cooling the bottom surface, it is possible to prevent the temperature gradient from being reduced by transferring heat of the molten region or the reaction region of aluminum in the oxidation process toward the unreacted region.

It is preferable to be in a high temperature state so that aluminum is melted for the oxidation reaction, but once the oxidation reaction is completed and converted into sapphire, which is a single crystal of aluminum oxide, cooling through temperature control is required.

If the sapphire thin film is not formed after proper annealing once formed, the sapphire thin film may be cracked or broken due to thermal stress due to cooling, and thus, from the temperature of the direct oxidation reaction to room temperature. The temperature needs to be adjusted to allow it to cool slowly.

In the step (B), the wavelength of the infrared ray or the laser and the line width of the locally heated portion are not limited, and may vary according to the thickness of the deposited aluminum thin film, and the heated portion is straight. Focusing on infrared or laser heaters as much as possible includes the use of reflectors, lenses and beam movement.

The infrared heating apparatus may use a phenomenon in which an infrared lamp is positioned at one of two focal points of an ellipse inside an ellipsoidal reflector, and the infrared rays reflected by the reflector are focused at another focus.

The laser heating apparatus changes a circular laser beam in a straight line using a lens on a path of a laser beam, or moves the beam along a straight line in a short time using a laser beam scanner or the like. It is possible to obtain a linear heating portion.

The linear width of the heated portion of the deposited aluminum varies according to the radius of curvature of the reflector and the filament size of the infrared lamp in the case of infrared heating, and varies according to the beam diameter of the laser in the case of laser heating, It is desirable to maintain a high temperature gradient necessary for crystal growth.

At this time, it is preferable that the said linear width is 3 mm or less.

The amount of energy delivered to the area to be heated depends on the output of the infrared lamp and the laser output, respectively, and the output can be adjusted.

When using a laser as a heat source, the laser type is a gas laser using carbon dioxide (CO ₂ ) or argon (Ar), an Nd-YAG laser, an LD laser using a laser diode, an X-ray laser, and an optical fiber. It includes a laser. The laser light source and infrared light source may include one or more light sources to ensure sufficient power for direct oxidation and single crystal growth.

The infrared or laser heating device may use one or more devices.

In order to oxidize the heated aluminum, oxygen gas preheated to a temperature range of 500 to 600 ° C. is injected into a region for oxidizing through a nozzle in a chamber for converting the aluminum into sapphire, wherein the partial pressure of oxygen in the chamber Should be kept constant within the range of 0 to 10 atm.

The outlet of the nozzle for introducing oxygen gas into the chamber may have a circular or quadrangular shape, and may be tilted or moved at a predetermined angle within the width of the quartz glass substrate on which the aluminum is deposited.

In the case where the nozzle has a rectangular shape close to a straight line, the length of the long side of the rectangle is within 1.2 times the width of the quartz glass substrate on which aluminum is deposited, and the size of the small side is preferably 1 mm or less. The angle is not particularly limited.

When the temperature of the preheated oxygen gas is lower than 500 ° C., the heated, fluidized and molten aluminum suddenly cools so that oxygen is not diffused in the fluidized and molten aluminum, making it difficult to cause oxidation in the deposited aluminum. If the temperature exceeds 600 ° C., energy consumption is high, which is undesirable from the economic point of view.

The growth front or growth interface in which the sapphire formed by the above method grows into a single crystal has a straight shape.

Since the heating part of aluminum is heated in a straight line with a narrow line width, the oxidation reaction zone heated at high temperature has a straight line shape, and a growth front where aluminum is oxidized and grows into sapphire single crystal in the oxidation reaction zone. Or the growth interface is also straight.

The direction of the linear growth interface or the linear heating portion maintains a constant direction within an angle range of θ = 0 to 90 ° with respect to the moving direction of the substrate.

This is to allow the single crystal growth to start from one edge of the deposited aluminum thin film to control the crystallographic direction of the grown sapphire single crystal thin film and to suppress the generation of polycrystal.

The method of cooling the bottom surface of the quartz glass substrate on which the aluminum is deposited includes a method of directly injecting a cooled inert fluid or a method of allowing a cooling fluid to flow in a tube contacting the bottom surface of the quartz glass substrate on which the aluminum is deposited. Included.

At this time, not only the temperature gradient of the oxidation reaction region can be adjusted according to the position where the cooling fluid is injected and the position of the cooling tube, but also the range of the slow cooling region that relaxes the thermal stress in the region where the oxidation reaction is completed and the sapphire thin film is formed. Can be set.

(C) In order to grow into a single crystal of sapphire while solidifying the sapphire produced in the step (B), the quartz glass substrate is continuously moved at a constant speed in the longitudinal direction of the quartz glass substrate, The board | substrate for LED chips in which the sapphire single crystal thin film was formed is manufactured.

If the moving speed is too fast in the longitudinal direction of the substrate for the sapphire single crystal growth, the melt fluidization of aluminum does not occur sufficiently, the time for the oxygen to react with aluminum in the oxidation reaction site is shortened and the time to convert to sapphire It is shorter, so the conversion to sapphire is not enough, and the single crystal growth of the converted sapphire is not enough, and the crystallinity decreases, so that the regular arrangement of atoms is likely to deviate from the perfect single crystal structure. Difficult to use

If the moving speed is too slow, there is a possibility of evaporation after the aluminum is dissolved in the reaction site, so that gaseous aluminum is present in the chamber to contaminate the chamber and to block infrared rays or laser beams from the heating device, which is undesirable in terms of economy.

In addition, in order to remove internal defects of the sapphire single crystal and to remove thermal residual stress after the oxidation reaction is completed, a plurality of infrared or laser heating devices may be provided.

In the present invention, the steps (A) and (B) are independent batch processes, but may be a continuous process.

In the continuous process, a sequential conversion vessel of oxygen pressure is provided between the chamber of step (A) and the chamber of step (B), and the quartz glass substrate is continuously moved through the sequential conversion vessel of oxygen pressure. Can be done.

The quartz glass substrate can be easily moved from the chamber of step (A) where the oxygen partial pressure is minimized by the sequential conversion vessel of the oxygen pressure to the chamber of step (B) where the oxygen partial pressure is present. It is preferable because the partial pressure of oxygen in the chamber can be kept constant.

Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings. This embodiment is only for illustrating the present invention, and the present invention is not limited to the following examples, and may be changed to other embodiments equivalent to substitutions and equivalents without departing from the technical spirit of the present invention. It will be apparent to those skilled in the art to which the invention pertains.

[Example]

A quartz glass substrate 5 cm long, 1 cm wide and 0.5 mm thick was prepared and placed in a sputtering apparatus, and placed in a tungsten container filled with 99.9% pure aluminum grains in an atmosphere of a mixed gas of 4% H ₂ + 96% Ar. A current of 220 V and 10 A was applied, and the tungsten vessel was heated to a temperature of 660 ° C. by the resistance exotherm of tungsten to dissolve aluminum and induce aluminum evaporation.

The evaporated aluminum particles were deposited on a quartz glass substrate heated to a temperature of 350 ° C. using a halogen lamp as a heat source, thereby obtaining a substrate on which 500 nm thick aluminum was deposited on the quartz glass substrate.

Figure 1a schematically shows a conceptual diagram and apparatus of a method for manufacturing a sapphire single crystal thin film for LED chip substrate by oxidation using an infrared heating device according to the present invention.

Figure 1b schematically shows a conceptual diagram and apparatus of a method of manufacturing a sapphire single crystal thin film for LED chip substrate by oxidation using a laser heating device according to the present invention.

In FIG. 1A, the infrared heater has an elliptic curvature radius with a long axis and short axis ratio of 0.88, and condenses a 1 kW infrared lamp using a reflector coated with gold (Au) on an internal reflection surface, thereby reducing the line width of the heating portion. It was formed to 3 mm.

The temperature of the heating portion was adjusted by changing the amount of current applied to the halogen lamp to be 660 ℃.

In this case, when using a laser beam without using an infrared lamp, a reflector is not required and the temperature of the heating part can be controlled by adjusting the output of the laser beam, thereby obtaining the same effect as an infrared lamp. In addition, the aluminum thin film on the aluminum-deposited substrate by a laser beam is locally heated in a straight line in a direction perpendicular to the longitudinal direction of the aluminum-deposited substrate.

At the same time, nitrogen gas at 25 ° C. was cooled while flowing at a rate of 100 cc / min into a copper tube contacting the bottom surface of the substrate on which aluminum was deposited, and the temperature of the cooled portion was adjusted to be 200 to 400 ° C.

In order not to interfere with the path of the infrared rays emitted from the halogen lamp, oxygen was released in the direction of the heating portion through a stainless metal nozzle having an internal diameter of 0.5 mm.

At this time, a cylindrical stainless steel container having a diameter of 10 cm and a length of 20 cm is wrapped in a band form in the middle of the chamber and the oxygen storage container, and a reaction in which oxygen of 99% purity heated to 500 to 600 ° C. is heated. Injection was made to the site.

The pressure was maintained at 1 atm in the chamber, but oxygen was injected so that the temperature distribution of the heating part did not change significantly due to the flow of oxygen injected.

Because of the small diameter of the nozzle at this stage, the shape of the outlet was circular, and the angle of about 45 ° from the surface of the deposited substrate was maintained so that the injected oxygen was directed toward the reaction site. The distance from the nozzle outlet to the surface of the reaction site was The injection amount of 1 cm and oxygen was maintained at 10 cc / min.

The sapphire single crystal thin film formed by the completion of the oxidation reaction by oxygen changes the focus of the halogen lamp in the chamber in which the direct oxidation reaction is carried out so that the infrared rays do not form a focal spot. The stress was removed.

At this time, the substrate was moved by the oxidation reaction as described above at a speed of 5 mm / hr in the chamber to prepare a substrate for an LED chip in which a sapphire single crystal thin film was formed on the final quartz glass substrate.

FIG. 2 shows the growth interface of the sapphire single crystal thin film by moving the deposited substrate by forming the heating focus of the infrared or laser beam in a straight line and locally heating the deposited aluminum in a straight line. It shows that the direction is constantly maintained within the angle range of θ = 0 to 90 ° with respect to the direction.

3 is a photograph showing that aluminum is converted into sapphire before and after the oxidation reaction according to the present invention.

4 is a scanning electron microscope microstructure photograph showing an aluminum region in which oxidation reaction is not completed and a sapphire single crystal region in which oxidation occurs when the aluminum metal thin film deposited on the quartz glass substrate according to the present invention is partially heat treated by a direct oxidation method. And Energy Dispersive Spectroscopy (EDS) analysis data.

In the zone where oxidation was completed, Al ₂ O ₃ , a sapphire component, was observed and Al was observed in the zone ②, which was not yet oxidized.

5 is a planar and cross-sectional scanning electron micrograph when the sapphire single crystal thin film is formed by the method according to the present invention, showing that a sapphire single crystal thin film has a very dense single crystal having a thickness of 100 nm.

6 is X-ray diffraction analysis results and EDS data of the sapphire single crystal thin film formed by the method according to the present invention.

The X-ray diffraction data shows that the aluminum oxide diffraction peak of sapphire clearly appears above the gentle diffraction peak of the quartz glass substrate, but no other peaks indicate that the aluminum oxide has grown in the c-axis direction. Obvious differences in the concentrations of aluminum, silicon, and oxygen can be observed around the grown sapphire interface.

In the present invention, a single chip thin film of sapphire was formed on a quartz glass substrate using a simplified two-step process by deposition and oxidation of aluminum through the above embodiment, and the formation of sapphire is shown in the EDS analysis data of FIG. 4. Was confirmed by.

In addition, it was confirmed that the thin sapphire single crystal thin film having a thickness of 100 nm is formed by FIG. 5, and the formation of the sapphire single crystal thin film was confirmed once again by FIG. 6.

DESCRIPTION OF SYMBOLS 1: Aluminum thin film, 2: Sapphire thin film, 3: Quartz glass substrate, 4: Melt fluidization reaction zone of aluminum, 5: Oxygen 6: Movement direction, 7: Halogen lamp, 8: Reflector, 9: Cooling tube, 10: Laser Heater, 11: laser beam

Claims (12)

(A) depositing aluminum to a thickness of 100-10000 nm on one surface of the quartz glass substrate;
(B) In the chamber for converting the aluminum into sapphire, locally heated the deposited aluminum so that the portion heated by the heating device is a straight line, and the undeposited underside of the quartz glass substrate on which the aluminum is deposited Cooling the portion to be cooled in a straight line while contacting oxygen with the heated aluminum, converting the aluminum by an oxidation reaction to form a sapphire single crystal, and slowly cooling the sapphire single crystal formed by the oxidation reaction; And
(C) a sapphire single crystal thin film for an LED chip substrate, comprising continuously moving the aluminum-deposited quartz glass substrate in the longitudinal direction or continuously moving the heating device in the longitudinal direction of the aluminum-deposited quartz glass substrate. Manufacturing method. delete The method of claim 1,
In the step (B), the heating device is an infrared or laser heating device, the linear width of the site heated by the heating device is 3 mm or less, the temperature of the heated site is 500 ~ 2100 ℃, the aluminum is Cooling temperature of the undeposited bottom surface of the deposited quartz glass substrate is -195.8 ~ 400.0 ℃ method for producing a sapphire single crystal thin film for the LED chip substrate. The method of claim 1,
The cooling of the undeposited bottom surface of the quartz glass substrate on which aluminum is deposited in step (B) forms a cooling portion in a direction parallel to the heated portion, and directly injects the cooled inert gas or directly A method of manufacturing a sapphire single crystal thin film for an LED chip substrate, comprising a method of allowing a cooling fluid to flow in a tube in contact with a bottom surface. The method of claim 1,
And (b) preheating the oxygen gas to 500 to 600 ° C. and injecting the oxygen gas into a region where the oxidation reaction occurs through a nozzle. The method of claim 1,
In the step (C), when the heating device is fixed, the quartz glass substrate on which the aluminum is deposited is moved, and when the aluminum glass is fixed, the LED chip substrate, characterized in that the heating device is moved. Method for producing a sapphire single crystal thin film. The method of claim 1,
The method of manufacturing a sapphire single crystal thin film for the LED chip substrate, characterized in that the moving speed of the quartz glass substrate on which aluminum is deposited in step (C) is 5 mm / hr. The method of claim 1,
A method for manufacturing a sapphire single crystal thin film for an LED chip substrate, characterized in that one or more heating devices can be used in the chamber. The method of claim 1,
Between the step (A) and the step (B), a sequential converting vessel of oxygen pressure is provided so that the step of continuously moving the quartz glass substrate through the sequential converting vessel of the oxygen pressure is further added. A method for producing a sapphire single crystal thin film for LED chip substrate, characterized in that. The method of claim 1,
Steps (A) and (B) are performed by a facility including an aluminum deposition apparatus on a quartz glass substrate and a chamber that forms a sapphire single crystal by an oxidation reaction in the quartz glass substrate on which the aluminum is deposited,
The chamber is a method of manufacturing a sapphire single crystal thin film for an LED chip substrate, characterized in that the heating device, the injection nozzle of oxygen gas, the injection tube for the cooling fluid. The method of claim 10,
The outlet of the injection nozzle of the oxygen gas has a circular, rectangular shape and can be tilted or moved at a predetermined angle within the width of the quartz glass substrate, the method of manufacturing a sapphire single crystal thin film for LED chip substrate. The LED chip manufactured by the method of any one of Claims 1, 3-11, and whose thickness of a sapphire single crystal thin film is 10-10000 nm.

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