KR100574541B1 - Light emitting diode and method for manufacturing light emitting diode - Google Patents

Abstract

The present invention provides a light emitting diode that can improve light efficiency and reduce power consumption by forming an undoped gallium nitride semiconducting layer having a low growth rate between a buffer layer and a gallium nitride (GaN) layer of a light emitting diode, and a method of manufacturing the same. Initiate. The disclosed invention includes a buffer layer disposed on a sapphire substrate; A slow growth gallium nitride layer disposed on the buffer layer; A gallium nitride layer disposed on the slow growth gallium nitride layer; A doped gallium nitride layer disposed on the gallium nitride layer; An active layer disposed on the doped gallium nitride layer; And a p-type gallium nitride layer disposed on the active layer.

Here, the low-growth gallium nitride layer is made of TMGa, NH ₃ , H ₂ material, the thickness of the low-growth gallium nitride layer is characterized in that 1 ~ 3000Å.

Light Emitting Diode, Gallium Nitride Layer, Slow Growth Gallium Nitride Layer, Buffer Layer

Description

LIGHT EMITTING DIODE AND METHOD FOR MANUFACTURING LIGHT EMITTING DIODE}

1 is a view showing a light emitting diode structure according to the prior art.

2A to 2D illustrate a light emitting diode manufacturing process according to the present invention.

* Description of the symbols for the main parts of the drawings *

200: sapphire substrate 201: buffer layer

203: slow growth gallium nitride layer (block layer) 205: undoped gallium nitride layer

207: n-type gallium nitride layer 209: active layer

210: P-type gallium nitride layer

The present invention relates to a light emitting diode and a method of manufacturing the same, and more particularly, to form an undoped gallium nitride layer (block layer) having a very slow growth rate on the n-type gallium nitride layer (GaN), thereby improving light efficiency A light emitting diode capable of operating with a current and a method of manufacturing the same.

In general, a light emitting diode (LED) is used to transmit and receive signals by converting electricity into infrared rays or light using characteristics of compound semiconductors, which are used in home appliances, remote controls, electronic displays, It is used for an indicator, various automation devices, and the like.

The operation principle of the LED is that when a forward voltage is applied to a semiconductor of a specific element, electrons and holes move and recombine with each other through a junction portion of a positive-negative and a positive-negative. Fall and light is emitted.

In addition, the LED is generally 0.25 mm 2, which is very small and manufactured in size, and is mounted on an epoxy mold, a lead frame, and a PCB. Currently, the most commonly used LEDs are 5mm (T 1 3/4) plastic packages or new types of packages depending on the specific application. The color of the light emitted by the LED creates a wavelength depending on the composition of the semiconductor chip components, and the wavelength determines the color of the light.

In particular, LEDs are becoming smaller and smaller, such as resistors, capacitors, and noise filters, due to the trend toward miniaturization and slimming of information and communication devices, and directly mounting them on a PCB (Printed Circuit Board) board. In order to make the surface mount device (Surface Mount Device) type.

Accordingly, LED lamps, which are used as display elements, are also being developed in SMD type. Such SMD can replace the existing simple lighting lamp, which is used for lighting indicators of various colors, character display and image display.

In recent years, as high-density integration technologies for semiconductor devices have been developed and consumers have demanded more compact electronic products, surface mount technology (SMT) has been widely used, and packaging technologies for semiconductor devices have also been known as ball grid array (BGA) and wire bonding. Technology to minimize the installation space, such as flip chip bonding.

1 is a view for explaining a light emitting diode manufacturing process according to the prior art.

As shown in FIG. 1, a GaN buffer layer 101 is formed on the sapphire substrate 100 made of Al ₂ O ₃ . Then, an Undoped GaN layer 103 is formed on the GaN buffer layer 101.

As described above, metal organic chemical vapor deposition (MOCVD) is generally used to grow a thin film of a group 3 series on the sapphire substrate 100. The growth pressure is 200 torr (torr) to The layer is formed while maintaining 650 torr.

An n-type GaN layer 105 is formed on the undoped GaN layer 103. To form the same, silicon using silicon tetrahydride (SiH 4) or silicon dihydrogen (Si ₂ H ₆ ) gas is used.

When the N-type gallium nitride layer (GaN) 105 is grown, an active layer 109 is grown on the N-type gallium nitride layer 105. The active layer 109 is a semiconductor layer to which a light emitting material made of indium gallium nitride (InGaN) is added. When the active layer 109 is grown, a P-type gallium nitride layer 110 is formed.

The P-type gallium nitride layer 110 is contrasted with the N-type gallium nitride layer 105. The N-type gallium nitride layer 105 moves electrons by a voltage applied to the outside, and the P-type gallium nitride layer 105 is relatively In the gallium nitride layer 110, holes are moved by a voltage applied to the outside, and holes and electrons in the active layer 109 combine with each other to emit light.

A transparent ITO metal layer (TM) is formed on the P-type gallium nitride layer 110 to transmit light generated from the active layer 109 to emit light to the outside.

After forming the transparent metal (TM) layer, a P electrode is formed to complete a light emitting diode.

However, the light emitting diode according to the prior art as described above has a problem that when the amount of light emission is increased to improve the brightness, the reliability of the diode is lowered and the light brightness of the light emitting diode is decreased to improve the reliability.

In order to improve the high brightness and high reliability as described above, the thermal radiation blocking of the active layer, the formation of a layer layer having an increased indium composition ratio, and the defect concentration control method of the gallium nitride layer are used, but such a process requires a separate process or two performances. There is a limit to satisfying at the same time.

SUMMARY OF THE INVENTION An object of the present invention is to provide a light emitting diode and a method of manufacturing the same, which are capable of improving breakdown voltage, low current driving, and light efficiency by forming a low-growth gallium nitride layer between a buffer layer and an undoped gallium nitride layer. .

In order to achieve the above object, a light emitting diode according to the present invention,

A buffer layer disposed on the sapphire substrate;

A slow growth gallium nitride layer disposed on the buffer layer;

A gallium nitride layer disposed on the slow growth gallium nitride layer;

An n-type gallium nitride layer disposed on the gallium nitride layer;

An active layer disposed on the n-type gallium nitride layer; And

And a p-type gallium nitride layer disposed on the active layer.

Here, the slow growth gallium nitride layer is formed using 0.001 ~ 10 μmol TMGa, 1000 ~ 100,000 sccm NH ₃ gas, 1000 ~ 100,000 sccm H ₂ gas, the thickness of the slow growth gallium nitride layer is 1 ~ It is characterized in that formed at a slower than the growth rate of the gallium nitride layer at 3000 kPa.

In addition, the light emitting diode manufacturing method according to the present invention,

Forming a buffer layer on the sapphire substrate;

Forming a slow growth gallium nitride layer on the buffer layer;

Forming a gallium nitride layer on the slow growth gallium nitride layer;

Forming an n-type gallium nitride layer on the gallium nitride layer;

Forming an active layer on the doped gallium nitride layer; And

Forming a p-type gallium nitride layer on the active layer; characterized in that it comprises a.

Here, the temperature for growing the slow growth gallium nitride layer is 1000 ℃ ~ 1500 ℃, the thickness of the slow growth gallium nitride layer is 1 ~ 3000Å, the slow growth gallium nitride layer is 0.001 ~ 10μmol TMGa, 1000 ~ 100,000 sccm of NH ₃ gas, 1000 ~ 100,000 sccm using H ₂ gas is characterized by forming by chemical vapor deposition method.

According to the present invention, an undoped gallium nitride layer having a very slow growth rate is formed between a buffer layer of a light emitting diode and a gallium nitride (GaN) layer, thereby improving light efficiency and reducing power consumption. .

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

2A to 2D are views for explaining a light emitting diode manufacturing process according to the present invention.

As shown in FIGS. 2A to 2D, a buffer layer having an In (x) Ga (1-x) N composition on a sapphire (Al ₂ O ₃ ) substrate 200 at a temperature of 500 to 600 ° C. (GaN buffer layer : 201), and a slow growth gallium nitride layer 203 is formed on the GaN buffer layer 201.

The slow growth gallium nitride layer 203 prevents defects in the buffer layer 201 from propagating to an undoped GaN layer 205 to be formed after the slow growth gallium nitride layer 203. It is a layer for.

The low-growth gallium nitride layer 203 is formed using a source (Metal Organic Source) in which a very small amount of metal and an organic material is formed after the buffer layer 201 is formed at 500 to 600 ° C.

The metal-organic source forms a layer by mixing TMGa with a source of the same kind as a source for growing an undoped gallium nitride layer.

As described above, when the slow-growing gallium nitride layer 203 uses a metal-organic material, since the growth of the layer is dominated by the horizontal growth rather than the vertical growth, the buffer layer 201 and the gallium nitride layer (GaN: 205) , 207 can be easily formed.

The material used for the low-growth gallium nitride layer 203 is formed by chemical vapor deposition using TM-Ga (Tri-metal Gallium), NH ₃ , H ₂ . Therefore, the existing manufacturing equipment and process can be used as it is, and the process is added once more only in the process of forming the low-growth gallium nitride layer 203.

Tri-metal Gallium (TMGa) is used as a source source for growth in an amount of 0.001-10 μmol, and NH ₃ and H ₂ are formed in a low-growth gallium nitride layer 203 by using an amount of 1000-100,000 sccm. do.

The temperature range at which the low-growth gallium nitride layer 203 is to be formed is greater than 500 to 600 ° C. at which the buffer layer 201 is formed, and is higher than the temperature to form the undoped gallium nitride layer (Un-GaN) 205 (900 to 1000). ℃) is grown at a high temperature of 1000 ℃ to 1500 ℃ equal or greater temperature.

The low-growth gallium nitride layer 203 is grown to have a thickness in the range of 1 to 3000 Å, and the low-growth gallium nitride layer 203 grows at a slower speed than that of the GaN layer 205.

When the slow-growing gallium nitride layer 203 is formed, an Un Doping GaN layer 205 is grown to a thickness of 1 to 6 µm at a temperature of 1000 to 1100 ° C. (FIG. 2C).

Then, an n-type GaN layer 207 is subsequently grown on the undoped GaN layer 205 at a temperature of 1000-1100 ° C. with a thickness of 1-6 μm (FIG. 2C).

When the n-type GaN layer 207 is formed, the active layer 209 having an InGaN / GaN structure having a multi-quantum well structure is subsequently grown at a temperature of 600 to 800 ° C.

When the active layer 209 is formed, the PGaN layer 210 doped with impurities of the Mg component is grown to a thickness of 750 to 1500 ° C at a temperature of 980 to 1020 ° C.

As described above, the surface of the buffer layer 201 formed on the sapphire substrate 200 according to the present invention has many defects in the growth process step, and these defects affect the gallium nitride layers 205 and 207 to be grown next. In order to prevent the light efficiency from falling, the light efficiency was improved by forming the low-growth gallium nitride layer 203 which prevents defect propagation from the buffer layer.

As described in detail above, the present invention forms a slow-growing gallium nitride layer in which a permeable metal is mixed between the buffer layer and the gallium nitride layer of the light emitting diode, thereby increasing breakdown voltage, improving low current driving performance, and improving light efficiency. The present invention is not limited to the above-described embodiments, and any person of ordinary skill in the art to which the present invention belongs without departing from the gist of the present invention as claimed in the following claims. Any number of changes could be made.

Claims (7)

A buffer layer disposed on the sapphire substrate; A slow growth gallium nitride layer disposed on the buffer layer; A gallium nitride layer disposed on the slow growth gallium nitride layer; An n-type gallium nitride layer disposed on the gallium nitride layer; An active layer disposed on the n-type gallium nitride layer; And And a p-type gallium nitride layer disposed on the active layer. The light emitting diode of claim 1, wherein the low-growth gallium nitride layer is formed using 0.001-10 μmol TMGa, 1000-100,000 sccm NH ₃ gas, and 1000-100,000 sccm H ₂ gas. The light emitting diode according to claim 1, wherein the low-growth gallium nitride layer has a thickness of 1 to 3000 kPa and is formed at a lower speed than the growth rate of the gallium nitride layer. Forming a buffer layer on the sapphire substrate; Forming a slow growth gallium nitride layer on the buffer layer; Forming a gallium nitride layer on the slow growth gallium nitride layer; Forming an n-type gallium nitride layer on the gallium nitride layer; Forming an active layer on the n-type gallium nitride layer; And Forming a p-type gallium nitride layer on the active layer; a light emitting diode manufacturing method comprising a. 5. The light emitting diode manufacturing method according to claim 4, wherein the temperature at which the low-growth gallium nitride layer is grown is 1000 ° C to 1500 ° C. 5. The light emitting diode manufacturing method according to claim 4, wherein the low-growth gallium nitride layer has a thickness of 1 to 3000 kPa and is formed at a lower speed than the growth rate of the gallium nitride layer. The method of claim 4, wherein the low-growth gallium nitride layer is formed by chemical vapor deposition using 0.001-10 μmol TMGa, 1000-100,000 sccm NH ₃ gas, and 1000-100,000 sccm H ₂ gas. Light emitting diode manufacturing method characterized in that.

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