KR20090004044A

KR20090004044A - Semiconductor light emitting device and fabrication method thereof

Info

Publication number: KR20090004044A
Application number: KR1020070067931A
Authority: KR
Inventors: 손효근
Original assignee: 엘지이노텍 주식회사
Priority date: 2007-07-06
Filing date: 2007-07-06
Publication date: 2009-01-12

Abstract

An embodiment of the present invention discloses a semiconductor light emitting device and a method of manufacturing the same.

A semiconductor light emitting device according to an embodiment of the present invention includes a conductive support; A laser light emitting part formed on one side of the conductive support part; It is formed on the other side of the conductive support portion, and includes a light emitting diode portion driven by the laser light emitting portion.

Description

Semiconductor light emitting device and method of manufacturing the same {Semiconductor light emitting device and fabrication method

Group III-V nitride semiconductors are spotlighted as core materials of light emitting devices such as light emitting diodes (LEDs) or laser diodes (LDs) due to their physical and chemical properties.

Ⅲ-Ⅴ nitride semiconductor is made of a semiconductor material having a compositional formula of normal _{In x Al y Ga 1 -x- y} N (0≤x≤1, 0 ≤y≤1, 0≤x + y≤1). LED or LD using such a nitride semiconductor material is widely used in the light emitting device for obtaining light in the blue or green wavelength band, and is applied as a light source of various products such as keypad light emitting part of the mobile phone, an electronic board, a lighting device.

1 is a side cross-sectional view of a conventional nitride semiconductor light emitting device, in particular showing a nitride semiconductor light emitting diode (LED) device.

Referring to FIG. 1, the light emitting device 10 has a structure in which an n-type GaN layer 13, an active layer 15, and a p-type GaN layer 17 are sequentially stacked on the sapphire substrate 11. The n-side electrode 19 is formed on the upper surface of the n-type GaN layer 13 exposed by mesa etching, and the p-side electrode 21 is formed on the upper surface of the p-type GaN layer 17.

The semiconductor light emitting device 10 performs a mesa etching process from the p-type GaN layer to a portion of the n-type GaN layer 13 to form the first electrode 19. Due to this etching process, the semiconductor light emitting device ( The epitaxial property of 10) is reduced, thereby reducing the light emitting area.

In addition, a current is supplied to the n-type GaN layer 13 through the first electrode 19. At this time, the first electrode 19 is biased to one side of the emission region, which causes a problem of current diffusion. In addition, there is a problem that the light emitting area is reduced by forming the second electrode 21 on the p-type GaN layer 17.

The semiconductor light emitting device 10 manufactured as described above has a weak static electricity resistance, a higher operating voltage than GaAs, and thus has problems such as heat generation and power consumption, resulting in poor reliability.

An embodiment of the present invention provides a semiconductor light emitting device capable of driving a light emitting diode using a laser and a method of manufacturing the same.

An embodiment of the present invention provides a semiconductor light emitting device and a method of manufacturing the same, wherein a laser unit and a light emitting diode unit are respectively formed on a conductive support, and the light emitting diode unit can be driven by laser light generated by the laser unit.

Method of manufacturing a semiconductor light emitting device according to an embodiment of the present invention comprises the steps of forming a conductive support; Forming a laser unit generating laser light on one side of the conductive support unit; Forming a light emitting diode part driven by laser light of the laser part on an upper portion of the other side of the conductive support part; And forming first and second electrodes on an upper side of the laser unit and on an upper side of the conductive support unit.

According to the embodiment of the present invention, it is possible to improve the reliability of the semiconductor light emitting device and to solve the problem of static resistance.

In addition, since a separate etching process or an electrode is not formed for the light emitting diode part, the light emitting efficiency can be increased.

Hereinafter, with reference to the accompanying drawings as follows.

2 is a view showing a semiconductor light emitting device according to an embodiment of the present invention, Figure 3 is a view showing an operating state of FIG.

2 and 3, the semiconductor light emitting device 100 includes a conductive support 110, a laser unit 120, a light emitting diode unit 130, a first electrode 151, and a second electrode 153. do.

The conductive support 110 is a base member for supporting the laser unit 120 and the light emitting diode unit 130, and a laser unit 120 for performing electrical emission is formed on one side of the conductive support 110. The light emitting diode unit 130 that performs optical emission is formed on the other side of the support 110.

The conductive support 110 includes a substrate 111, an undoped semiconductor layer, and a first n-type semiconductor layer 115, and the substrate 111 includes sapphire (Al ₂ O ₃ ), silicon carbide (SiC), and gallium. It may be made of any one selected from aceite (GaAs) and the like.

An undoped semiconductor layer 113 may be formed on the substrate 111, and the undoped semiconductor layer may be implemented as an undoped GaN layer. In addition, a GaN-based buffer layer may be formed between the substrate 111 and the undoped semiconductor layer. Only one of the undoped semiconductor layer 113 and the buffer layer may or may not be formed.

The first n-type semiconductor layer 115 is formed on the undoped semiconductor layer 113. The 1n-type semiconductor layer 115 may be implemented by any one of a GaN compound semiconductor such as a GaN layer, an AlGaN layer, an InGaN layer, and the like, and is doped with an n-type dopant.

The laser unit 120 is formed on the conductive support 110, that is, on one side above the first n-type semiconductor layer 115. The laser unit 120 includes a second n-type semiconductor layer 121, a first active layer 123, a first p-type semiconductor layer 125, and a second p-type semiconductor layer 127.

The second n-type semiconductor layer 121 may be formed in a superlattice structure using a GaN-based compound semiconductor, and the period of the AlGaN layer and the GaN layer may be formed on the first n-type semiconductor layer 115 with a period of 25 to 50 cycles. Can be. The second n-type semiconductor layer 121 serves as a lower mirror of the laser unit 120.

The first active layer 123 may be formed of a single quantum well or multiple quantum well structure, and includes a GaN or AlGaN quantum barrier layer and an InGaN quantum well layer. The first active layer 123 emits laser light, for example, light having a wavelength of 325 to 405 nm.

A first p-type semiconductor layer 125 is formed on the first active layer 123, and the first p-type semiconductor layer 125 may be formed in a superlattice structure using a GaN compound, for example, an AlGaN layer and GaN. It can be formed into a superlattice structure with a period of layers. The first p-type semiconductor layer 125 serves as an upper mirror of the laser unit 120.

The second p-type semiconductor layer 127 is formed on the first p-type semiconductor layer 125. The second p-type semiconductor layer 127 may be implemented by any one of a GaN compound semiconductor such as a GaN layer, an AlGaN layer, an InGaN layer, and the like, and is doped with a p-type dopant.

The light emitting diode unit 130 is formed on the other side of the conductive support 110. The light emitting diode unit 130 includes a third n-type semiconductor layer 131, a second active layer 133, and a protective layer 135.

The 3n type semiconductor layer 131 is formed on the 1n type semiconductor layer 115, and the 1n type semiconductor layer 115 is implemented by any one of GaN compound semiconductors such as a GaN layer, an AlGaN layer, an InGaN layer, or the like. N-type dopant may be doped.

A second active layer 133 is formed on the third n-type semiconductor layer 131, and the second active layer 133 may be formed as a single quantum well or a multiple quantum well structure, and may include a GaN or AlGaN quantum barrier layer and an InGaN. A quantum well layer. The second active layer 133 generates light having a blue or green wavelength.

A protective layer 135 is formed on the second active layer 133, and the protective layer 135 may be implemented as an undoped GaN cap layer.

The first electrode 151 is formed on the first n-type semiconductor layer 115 of the conductive support 110, and the second electrode 153 is formed on the second p-type semiconductor layer 127. When the first electrode 151 and the second electrode 153 are formed, an area excluding the first electrode and the second electrode 151 and 153, that is, the surface of the conductive support 110 and the surface and side surfaces of the laser unit 120. The insulating layer 141 is formed on the surface and side surfaces of the light emitting diode unit 130. The insulating layer 141 may be implemented with SiO ₂ .

When the semiconductor light emitting device applies a forward bias current through the first electrode 151 and the second electrode 153, as shown in FIG. 3, in the first active layer 123 of the laser unit 120. The light of the laser wavelength is generated, and the light of the laser wavelength is transmitted to the second active layer 133 of the light emitting diode unit 130 to drive the second active layer 123 to generate light of blue or green wavelength. Will occur.

4 to 10 illustrate a method of manufacturing a semiconductor light emitting device according to an embodiment of the present invention.

Referring to FIG. 4, the undoped semiconductor layer 113 and the first n-type semiconductor layer 115 are sequentially stacked on the substrate 111 to form the conductive support 110. A laser unit 120 is formed on the first n-type semiconductor layer 115 of the conductive support 110, and the laser unit 120 is a second n-type semiconductor layer 121 on the first n-type semiconductor layer 115. An AlGaN / GaN superlattice layer is formed, and a first active layer 123 is formed on the second n-type semiconductor layer 121, and AlGaN / is a first p-type semiconductor layer 125 on the first active layer 123. A GaN superlattice layer is formed. In addition, an AlGaN, GaN, InGaN layer, which is a second p-type semiconductor layer 127, may be selectively formed on the first p-type semiconductor layer 125.

Referring to FIG. 5, a portion of the laser unit 120 is partially etched to a part of the surface of the first n-type semiconductor layer 115 through a photo process and an etching process.

Referring to FIG. 6, the light emitting diode unit 130 is formed by using semiconductor growth equipment (eg, MOCVD). The light emitting diode unit 130 forms a third n-type semiconductor layer 131 on the first n-type semiconductor layer 115 and the second p-type semiconductor layer 127, and a second layer on the third n-type semiconductor layer 131. The active layer 133 is formed. An undoped GaN cap layer, which is a protective layer 135, is formed on the second active layer 133.

Referring to FIG. 7, when the stacking of the components of the light emitting diode unit 130 is completed, the photoresist and the etching process may be removed up to the surface height of the second p-type semiconductor layer 127. A photoresist pattern 136 is formed on the exposed protective layer 135, and as shown in FIG. 8, the first n-type semiconductor layer is formed in a region other than the photoresist pattern 136 and the laser unit 120. Partial etching is performed until 115 is exposed. Here, the etching method may be a dry or wet etching method.

Referring to FIG. 9, the photoresist pattern formed on the protective layer 135 is removed.

Referring to FIG. 10, the first electrode 151 is formed on the first n-type semiconductor layer 115 exposed to the conductive support 110, and the second electrode 153 is formed on the second p-type semiconductor layer 127. By forming, a semiconductor light emitting element is completed. In addition, the insulating layer 141 may be formed on the exposed surface of the conductive support part 110, the laser part 120, and the light emitting diode part 130 of the semiconductor light emitting device.

In the semiconductor light emitting device, the light emitting diode portion is not etched or the electrode is formed, and light is generated by using the laser wavelength, thereby ensuring electrical and optical reliability.

In addition, it is possible to minimize the deterioration of characteristics generated during the growth of the light emitting diode unit 130, to eliminate the problem of electrostatic resistance, and to improve the deterioration of the characteristics of the LED chip generated due to heat generation during electric shock or other lighting.

In the description of an embodiment according to the present invention, each layer (film), region, pattern or structure is "on" or "under" the substrate, each layer (film), region, pad or patterns. In the case where it is described as being formed in, "on" and "under" include both the meaning of "directly" and "indirectly".

The present invention has been described above with reference to the preferred embodiments, which are merely examples and are not intended to limit the present invention, and those skilled in the art to which the present invention pertains do not depart from the essential characteristics of the present invention. It will be appreciated that various modifications and applications are not possible that are not illustrated above. For example, each component specifically shown in the embodiment of the present invention can be modified. And differences relating to such modifications and applications will have to be construed as being included in the scope of the invention defined in the appended claims.

1 is a cross-sectional view showing a conventional semiconductor light emitting device.

2 is a cross-sectional view showing a semiconductor light emitting device according to an embodiment of the present invention.

3 is a view showing the operating state of FIG.

4 to 10 are views showing a manufacturing process of a semiconductor light emitting device according to an embodiment of the present invention.

100 semiconductor light emitting device 110 conductive support portion

111 substrate 113 undoped semiconductor layer

113,121,131: n-type semiconductor layer 120: laser portion

123,133: active layer 125,127: p-type semiconductor layer

130: light emitting diode portion 135: protective layer

141: insulating layer 151, 153: electrode

Claims

Conductive support;

A laser light emitting part formed on one side of the conductive support part;

A semiconductor light emitting device formed on the other side of the conductive support and including a light emitting diode part driven by the laser light emitting part;

The method of claim 1,

The conductive support may include a substrate; An undoped semiconductor layer formed on the substrate; A semiconductor light emitting device comprising a first n-type semiconductor layer formed on the undoped semiconductor layer.

The method of claim 1,

The laser light emitting unit includes a second n-type semiconductor layer; A first active layer formed on the second n-type semiconductor layer; And a first p-type semiconductor layer formed on the active layer and a second p-type semiconductor layer formed on the first p-type semiconductor layer.

The method of claim 3, wherein

A semiconductor light emitting device comprising a first electrode formed on the first n-type semiconductor layer and a second electrode formed on the second p-type semiconductor layer.

The method of claim 1,

The light emitting diode unit may include a third n-type semiconductor layer; A semiconductor light emitting device comprising a second active layer formed on the third n-type semiconductor layer.

The method of claim 5,

A semiconductor light emitting device comprising a protective layer formed on the second active layer.

The method of claim 3, wherein

The second n-type semiconductor layer is a semiconductor light emitting device having a cycle of AlGaN layer and GaN layer is formed in a super lattice structure.

The method of claim 3, wherein

The first p-type semiconductor layer is a semiconductor light emitting device having a cycle of AlGaN layer and GaN layer is formed in a super lattice structure.

The method of claim 3, wherein

And the second n-type semiconductor layer and the first p-type semiconductor layer serve as mirrors of a laser unit.

The method according to claim 3 or 5,

The active layer is a semiconductor light emitting device having a single quantum or multiple quantum well structure.

The method of claim 1,

A semiconductor light emitting device comprising an insulating layer formed on a portion of the surface of the conductive support, the laser portion and the light emitting diode portion.

Forming a conductive support;

Forming a laser unit generating laser light on one side of the conductive support unit;

Forming a light emitting diode part driven by the laser light of the laser part on the other side of the conductive support part;

And forming a first electrode on the conductive support and forming a second electrode on the laser.

The method of claim 12,

The forming of the conductive support may include forming an undoped semiconductor layer on a substrate; A method of manufacturing a semiconductor light emitting device, comprising the step of forming a first n-type semiconductor layer on the und semiconductor layer.

The method of claim 13,

The forming of the laser light emitting part may include forming a second n-type semiconductor layer on the first n-type semiconductor layer; Forming a first active layer on the second n-type semiconductor layer; Forming a first p-type semiconductor layer on the active layer; Forming a second p-type semiconductor layer on the first p-type semiconductor layer; And partially etching the portion of the second p-type semiconductor layer until the first n-type semiconductor layer is exposed.

The method of claim 14,

The forming of the light emitting diode part may include forming a third n-type semiconductor layer on the exposed first n-type semiconductor layer and the second p-type semiconductor layer; Forming a second active layer on the third n-type semiconductor layer; Forming a protective layer on the second active layer; Partially etching the protective layer until the surface of the second p-type semiconductor layer is exposed; Forming a photoresist pattern on the passivation layer, and then etching the photoresist pattern to a region other than the second p-type semiconductor layer and the passivation layer until the 1n-type semiconductor layer is exposed.

The method of claim 15,

The protective layer is a semiconductor light emitting device manufacturing method implemented as an undoped GaN cap layer.

The method of claim 14,

The second n-type semiconductor layer and the first p-type semiconductor layer is a semiconductor light emitting device manufacturing method is formed in a superlattice structure with a period of the AlGaN layer and GaN layer.

The method of claim 12,

Forming an insulating layer to protect the surface of the conductive support, the laser portion and the light emitting diode portion.