KR20180087682A - Semiconductor device - Google Patents

Abstract

Disclosed is a semiconductor device with improved light extraction efficiency. The semiconductor device comprises a plurality of light emitting structures including a first conductive semiconductor layer, a second conductive semiconductor layer, an active layer disposed between the first and second conductive semiconductor layers, a first recess penetrating through the second conductive semiconductor layer and the active layer to be disposed to a partial region of the first conductive semiconductor layer, and a second recess penetrating through the first conductive semiconductor layer; a first electrode disposed on the first recess and electrically connected to the first conductive semiconductor layer; and a reflective layer disposed under the second conductive semiconductor layer.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001]

Embodiments relate to semiconductor devices.

Semiconductor devices including compounds such as GaN and AlGaN have many merits such as wide and easy bandgap energy, and can be used variously as light emitting devices, light receiving devices, and various diodes.

Particularly, a light emitting device such as a light emitting diode or a laser diode using a semiconductor material of Group 3-5 or 2-6 group semiconductors can be applied to various devices such as a red, Blue, and ultraviolet rays. By using fluorescent materials or combining colors, it is possible to realize a white light beam with high efficiency. Also, compared to conventional light sources such as fluorescent lamps and incandescent lamps, low power consumption, , Safety, and environmental friendliness.

In addition, when a light-receiving element such as a photodetector or a solar cell is manufactured using a semiconductor material of Group 3-5 or Group 2-6 compound semiconductor, development of a device material absorbs light of various wavelength regions to generate a photocurrent , It is possible to use light in various wavelength ranges from the gamma ray to the radio wave region. It also has advantages of fast response speed, safety, environmental friendliness and easy control of device materials, so it can be easily used for power control or microwave circuit or communication module.

Accordingly, the semiconductor device can be replaced with a transmission module of an optical communication means, a light emitting diode backlight replacing a cold cathode fluorescent lamp (CCFL) constituting a backlight of an LCD (Liquid Crystal Display) display device, White light emitting diodes (LEDs), automotive headlights, traffic lights, and gas and fire sensors. In addition, semiconductor devices can be applied to high frequency application circuits, other power control devices, and communication modules.

In particular, a light emitting device that emits light in the ultraviolet wavelength range can be used for curing, medical use, and sterilization by curing or sterilizing action.

In the conventional semiconductor device, the light generated in the active layer may proceed in the side or lower direction in addition to the upper direction of the active layer. Therefore, there is a problem that the light propagation path of the light emitted from the semiconductor device is lengthened or absorbed inside the light emitting structure.

The embodiment provides a semiconductor device with improved light extraction efficiency.

Embodiments provide a semiconductor device with improved light output and reduced operating voltage.

The embodiment provides a semiconductor device with improved reliability.

A semiconductor device according to an embodiment of the present invention includes a first conductive semiconductor layer, a second conductive semiconductor layer, an active layer disposed between the first conductive semiconductor layer and the second conductive semiconductor layer, Type semiconductor layer and a first recess disposed through a part of the first conductivity type semiconductor layer through the active layer; And a second recess penetrating the first conductive semiconductor layer; A first electrode disposed in the first recess and electrically connected to the first conductive semiconductor layer; And a reflective layer disposed under the second conductive type semiconductor layer.

The second recess may include a stepped portion.

The width of the stepped portion may be 1: 1.3 to 1:10, and the ratio of the width from one end of the stepped portion adjacent to the second electrode to the one end of the exposed second recessed portion adjacent to the stepped portion may be 1: 1.3 to 1:10.

The distance between the upper surface of the second electrode and the stepped portion may be the same as the distance between the upper surface of the second electrode and the surface of the first electrode contacting the first conductive type semiconductor layer.

The thickness of the reflective layer may be 0.5 탆 to 1 탆.

And a second electrode pad electrically connected to the reflective layer.

And a second electrode disposed between the second conductive semiconductor layer and the reflective layer.

The reflective layer may be electrically connected to the second electrode.

And a bonding layer disposed under the first recess and the first electrode.

And a substrate disposed under the bonding layer and electrically connected to the bonding layer.

An electronic device according to an embodiment includes: a semiconductor element; And a case accommodating the semiconductor element.

According to the embodiment, the semiconductor device can improve the light extraction efficiency.

Further, the light output can be improved.

In addition, a semiconductor device with improved reliability can be provided.

The various and advantageous advantages and effects of the present invention are not limited to the above description, and can be more easily understood in the course of describing a specific embodiment of the present invention.

1 is a plan view of a semiconductor device according to an embodiment,
FIG. 2 is a cross-sectional view of the semiconductor device according to the embodiment in the direction AA 'of FIG. 1,
3 is a cross-sectional view for explaining thickness and distance in Fig. 2,
Fig. 4 is an enlarged view of D in Fig. 3,
Fig. 5 is a partially enlarged view of Fig. 1,
6A to 6F are views showing a method of manufacturing a semiconductor device according to an embodiment of the present invention.

The embodiments may be modified in other forms or various embodiments may be combined with each other, and the scope of the present invention is not limited to each embodiment described below.

Although not described in the context of another embodiment, unless otherwise described or contradicted by the description in another embodiment, the description in relation to another embodiment may be understood.

For example, if the features of configuration A are described in a particular embodiment, and the features of configuration B are described in another embodiment, even if the embodiment in which configuration A and configuration B are combined is not explicitly described, It is to be understood that they fall within the scope of the present invention.

In the description of the embodiments, in the case where one element is described as being formed "on or under" another element, the upper (upper) or lower (lower) or under are all such that two elements are in direct contact with each other or one or more other elements are indirectly formed between the two elements. Also, when expressed as "on or under", it may include not only an upward direction but also a downward direction with respect to one element.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art can easily carry out the present invention.

FIG. 1 is a plan view of a semiconductor device according to an embodiment, and FIG. 2 is a cross-sectional view of a semiconductor device according to an embodiment in a direction AA 'in FIG.

Referring to FIG. 1, a semiconductor device according to an embodiment of the present invention may include a plurality of light emitting structures. The number of the light emitting structures can be variously applied, and accordingly, the size of the semiconductor device can be modified.

2, a semiconductor device according to an embodiment includes a plurality of light emitting structures 120, a first insulating layer 130, a reflective layer 140, a second insulating layer 150, a bonding layer 160, a substrate 170 ).

The light emitting structure 120 includes a first conductive semiconductor layer 122, a second conductive semiconductor layer 124, an active layer 122 disposed between the first conductive semiconductor layer 122 and the second conductive semiconductor layer 124, The first conductive semiconductor layer 122 and the first conductive semiconductor layer 122 are formed to reach the first conductive semiconductor layer 122 through the first conductive semiconductor layer 123 and the second conductive semiconductor layer 124 and the active layer 123, And a second recess 126 through the first recess 122.

The light emitting structure 120 according to the embodiment may generate light in an ultraviolet wavelength band.

For example, the light emitting structure 120 may output the light UV-A at the near ultraviolet wavelength band, the light UV-B at the far ultraviolet wavelength band, the light at the ultraviolet wavelength band UV- ). ≪ / RTI > The ultraviolet wavelength band can be determined by the composition ratio of Al in the light emitting structure 120.

Illustratively, the near ultraviolet light (UV-A) may have a wavelength in the range of 320 to 420 nm, the far ultraviolet light (UV-B) may have a wavelength in the range of 280 nm to 320 nm, The light of the wavelength band (UV-C) may have a wavelength in the range of 100 nm to 280 nm.

The first conductive semiconductor layer 122 may be disposed on the light emitting structure 120. The first conductivity type semiconductor layer 122 includes a first conductivity type semiconductor layer 122b disposed adjacent to the active layer 123 and a first conductivity type semiconductor layer 122b disposed on the first conductivity type semiconductor layer 122b. Type semiconductor layer 122a.

The first-conductivity-type semiconductor layer 122a and the first-conductivity-type semiconductor layer 122b may have different Al compositions. For example, the first conductivity type semiconductor layer 122a may be a layer having a high Al composition, and the first conductivity type semiconductor layer 122b may be a layer having a low Al composition. The lower surface of the first conductivity type semiconductor layer 122a may be in contact with the upper surface of the first electrode 182 to be electrically connected.

The first conductive semiconductor layer 122 may be formed of a compound semiconductor such as a group III-V and a group II-VI, and the first conductive semiconductor layer 122 may be doped with a first dopant. The first conductive semiconductor layer 122 may be a semiconductor material having a composition formula of Inx1Aly1Ga1-x1-y1N (0? X1? 1, 0? Y1? 1, 0? X1 + y1? 1), for example, GaN, AlGaN, InGaN, InAlGaN, and the like. The first dopant may be an n-type dopant such as Si, Ge, Sn, Se, or Te. When the first dopant is an n-type dopant, the first conductivity type semiconductor layer 122 doped with the first dopant may be an n-type semiconductor layer.

The composition of the first conductivity type semiconductor layer 122a may be 55% to 70%, and the composition of the first conductivity type semiconductor layer 122b may be 40% to 55%. The first and second conductivity type semiconductor layers 122b may be disposed adjacent to the active layer 123.

The active layer 123 may be disposed between the first conductive semiconductor layer 122 and the second conductive semiconductor layer 124. The active layer 123 is a layer where electrons (or holes) injected through the first conductive type semiconductor layer 122 and holes (or electrons) injected through the second conductive type semiconductor layer 124 meet. As the electrons and the holes are recombined, the active layer 123 transitions to a low energy level and can generate light having a wavelength corresponding thereto.

The active layer 123 may have any one of a single well structure, a multiple well structure, a single quantum well structure, a multi quantum well (MQW) structure, a quantum dot structure, Is not limited thereto. The active layer 123 may include Al.

The second conductive semiconductor layer 124 may be disposed under the active layer 123. The second conductive semiconductor layer 124 may be electrically connected to the second electrode 186.

The second conductive semiconductor layer 124 may be formed of a compound semiconductor such as group III-V, group II-VI, or the like. A second dopant may be doped in the second conductive semiconductor layer 124. The second conductive semiconductor layer 124 may be a semiconductor material having a composition formula of Inx5Aly2Ga1-x5-y2N (0? X5? 1, 0? Y2? 1, 0? X5 + y2? 1) or a semiconductor material having a composition formula of AlInN, AlGaAs, GaP, GaAs , GaAsP, and AlGaInP. When the second dopant is a p-type dopant such as Mg, Zn, Ca, Sr, or Ba, the second conductivity type semiconductor layer 124 doped with the second dopant may be a p-type semiconductor layer.

The first recess 125 may extend through the second conductive semiconductor layer 124 and the active layer 123 and may extend to a portion of the first conductive semiconductor layer 122. The first recess 125 may be at least one or more in the light emitting structure. The first electrode 182 is disposed inside the first recess 125 and may be electrically connected to the first conductive semiconductor layer 122.

The second recess 126 may be disposed to penetrate the first conductive semiconductor layer 122. The second recess 126 may be at least one within the light emitting structure 120. A second electrode 186 may be disposed between the second recess and the first recess 125.

The second recess 126 may include a step 126a. The distance between the upper surface of the second electrode 186 and the step portion 126a is equal to the distance between the upper surface of the second electrode 186 and the surface of the first electrode 182 that is in contact with the first conductive type semiconductor layer 122 can do. This configuration may be because the mesa etch is performed identically. However, the present invention is not limited thereto.

A reflective layer 140 may be disposed in the second recess 126 and an upper surface of the reflective layer 140 may define the same surface as the upper surface of the light emitting structure 120.

The second recess 126 may structurally separate the first conductivity type semiconductor layer 122. With this structure, the path of light generated in the active layer 123 by the first conductivity type semiconductor layer 122 is reduced, so that the optical loss due to the movement is reduced, and the light extraction efficiency can be improved.

The first insulating layer 130 may extend from the bottom of the light emitting structure 120 into the first recess 125 and into the second recess 126. The first insulating layer 130 may electrically isolate the first conductive semiconductor layer 122 from the second conductive semiconductor layer 124.

The thickness of the first insulating layer 130 may be 0.1 탆 to 0.7 탆, but is not limited thereto. If the thickness of the first insulating layer 130 is 0.1 탆 or less, the electrical reliability may be weakened. When the thickness of the first insulating layer 130 is 0.7 μm or more, a difference in thermal expansion coefficient (CTE) between the reflective layer 140 and the first insulating layer 130 or a difference in thermal expansion coefficient (CTE) between the reflective layer 140 and the first insulating layer 130 The reflective layer 140 may be peeled or cracked due to the stress, which may cause a problem that the electrical reliability of the semiconductor device deteriorates or the light extraction efficiency deteriorates.

The first insulating layer 130 may include at least one of silicon oxide (SiOx), silicon nitride (SiNy), and aluminum oxide (AlxOy), but the present invention is not limited thereto. The first insulating layer 130 may be disposed of a material having a refractive index lower than that of the light emitting structure 120.

The reflective layer 140 may be disposed under the first insulating layer 130 and the second conductive semiconductor layer 124. The reflective layer 140 may be electrically connected to the second conductive semiconductor layer 124. The reflective layer 140 may cover the second electrode 186 and may be electrically connected to the second electrode 186.

The reflective layer 140 may extend from the lower surface of the second conductive semiconductor layer 124 to a portion of the first recess 125. The reflective layer 140 may extend from the bottom surface of the second conductivity type semiconductor layer 124 to the inside of the second recess 126.

The reflective layer 140 may be disposed on the lower surface of the second conductivity type semiconductor layer 124 to reflect light emitted from the active layer 123 to the upper portion of the light emitting structure 120. The reflective layer 140 extends into the first and second recesses 125 and 126 to reflect the light emitted from the active layer 123 to the upper portion of the light emitting structure 120 to allow the light to escape to the outside Can be blocked. Therefore, the reflection layer 140 can improve the luminous flux emitted by the semiconductor element, and can control the directivity angle of the semiconductor element.

The reflective layer 140 may include a first electrode 182 disposed within the first recess 125 and a bonding layer 160 disposed within the first recess 125. The reflective layer 140 may include a first electrode 182 and a bonding layer 160 disposed within the first recess 125, As shown in FIG. Accordingly, the reflective layer 140 may reflect light emitted to the side surface and the upper surface of the first recess 125 to the upper portion of the light emitting structure 120.

The first electrode 182 and the second electrode 186 may be short-circuited when the reflective layer 140 is in direct contact with the first electrode 182 and the bonding layer 160. Also, the first electrode 182 and the bonding layer 160 may be short-circuited. Because of this, current can not be injected into the light emitting structure 120, so that the semiconductor element can malfunction.

Therefore, the shortest distance between the reflective layer 140 and the first electrode 182 disposed to a partial region of the upper portion of the first recess 125 may have a separation distance of 1 탆 to 15 탆. Here, the separation distance may be a length of X axis direction (X- _1, X ₂ axis direction). If the distance between the reflective layer 140 and the first electrode 182 is less than 1 탆, the process margin for ensuring the distance between the reflective layer 140 and the first electrode 182 is insufficient, . If the reflective layer 140 and the first electrode 182 do not have a distance, the first electrode 182 and the reflective layer 140 are electrically connected to each other to cause the semiconductor device to malfunction.

In addition, when the semiconductor device is operated for a long time, the first electrode 182 and the reflective layer 140 may be short-circuited due to migration of atoms of the reflective layer 140. When the distance between the reflective layer 140 and the first electrode 182 is greater than 15 μm, the area of the upper portion of the first recess 125 becomes larger, so that the area of the active layer 123 of the light emitting structure 120 is reduced, The light flux emitted by the light source 120 and the semiconductor element may be lowered.

In addition, the reflective layer 140 may be electrically connected to the second electrode pad 146. The power supplied from the second electrode pad 146 may be provided as the second conductivity type semiconductor through the reflective layer 140 and the second electrode 186. [ The thickness of the reflective layer 140 may be 0.03 탆 to 1 탆 or 0.8 탆 to 1 탆.

As the reflective layer 140, a material having a high reflectivity at an ultraviolet wavelength band may be selected. The reflective layer 140 may include a conductive material. Illustratively, the reflective layer 140 may include Al or the like, but is not limited thereto.

The second insulating layer 150 may be disposed under the reflective layer 140 and the first recess 125. The second insulating layer 150 may electrically isolate the bonding layer 160 and the substrate 170 from the reflective layer 140. The thickness of the second insulating layer 150 may be 0.5 탆 to 1 탆, but is not limited thereto.

If the thickness of the second insulating layer 150 is less than 0.5 탆, the electrical reliability in operation of the semiconductor device may deteriorate. If the thickness of the second insulating layer 150 is 1 占 퐉 or more, the reliability of the semiconductor device may deteriorate due to the pressure or thermal stress applied to the device during the process, and the light extraction efficiency may deteriorate.

The bonding layer 160 may be disposed below the second insulating layer 150 or below the first electrode 182. The bonding layer 160 may be electrically connected to the first electrode 182. A second insulating layer 150 may be disposed between the bonding layer 160 and the reflective layer 140. The second insulation layer 150 may be disposed such that the reflection layer 140 and the bonding layer 160 are electrically separated from each other. The bonding layer 160 may bond the light emitting structure 120 with the substrate 170 disposed under the light emitting structure 120.

The bonding layer 160 may include a conductive material. Illustratively, the bonding layer 160 may comprise at least one of gold, tin, indium, aluminum, silicon, silver, nickel, and copper.

The substrate 170 may be disposed under the bonding layer 160. The substrate 170 may be formed of a conductive material such as a metal. The substrate 170 may be electrically connected to the bonding layer 160. Illustratively, substrate 170 may comprise a metal or semiconductor material. The substrate 170 may be a metal having excellent electrical conductivity and / or thermal conductivity. In this case, the heat generated during semiconductor device operation can be quickly dissipated to the outside.

The substrate 170 may include at least one of silicon, molybdenum, silicon, tungsten, copper, and aluminum. However, the present invention is not limited thereto.

The first electrode 182 may be disposed within the first recess 125. The first electrode 182 may be disposed on the lower surface of the first conductive semiconductor layer 122b. With such a configuration, the semiconductor element can secure a relatively good current injection characteristic. The first electrode 182 is formed on the first conductivity type semiconductor layer 122a because the first conductivity type semiconductor layer 122a has a higher Al composition than the first conductivity type semiconductor layer 122b, May be disposed on the lower surface of the first conductive semiconductor layer 122b.

The first electrode 182 may be electrically connected to the first conductive semiconductor layer 122. The thickness of the first electrode 182 may be 0.2 탆 to 0.3 탆. However, the present invention is not limited thereto.

The thickness of the first electrode 182 may be thinner than the thickness of the first insulating layer 130. The first insulating layer 130 may partially cover the first electrode 182. In addition, the first electrode 182 and the first insulating layer 130 may form a spaced-apart space. The shortest distance between the first insulating layer 130 and the first electrode 182 may be 0.3 탆 to 0.5 탆. If the shortest distance is less than 0.3 mu m, the second insulating layer 150 may be difficult to arrange because the distance for disposing the second insulating layer 150 disposed at the shortest distance is too narrow. As a result, cracking or peeling may occur in the second insulating layer 150. The reliability of the semiconductor device may be deteriorated.

The area of the active layer 123 of the light emitting structure 120 is decreased and the light flux emitted from the light emitting structure 120 is lowered because the area of the first recess 125 is too wide, . The thickness of the first electrode 182 may be 40% to 80% of the thickness of the first insulating layer 130.

The thickness of the first electrode 182 may be 40% to 80% of the thickness of the first insulating layer 130. If the thickness of the first electrode 182 is less than 40% of the thickness of the first insulating layer 130, problems such as peeling and cracking may occur due to the degradation of the step coverage characteristic occurring when the lower electrode layer is disposed.

If the thickness of the first electrode 182 is greater than 80% of the thickness of the first insulating layer 130, the second insulating layer 140 may be spaced apart from the first insulating layer 130 and the first electrode 182 May be disposed within a distance. At this time, the gap-fill characteristic of the second insulating layer 140 is lowered, and cracking or peeling may occur in the second insulating layer 140.

The second electrode 186 may be disposed between the second conductive semiconductor layer 124 and the reflective layer 140. The second electrode 186 may be electrically connected to the reflective layer 140. The second electrode 186 may be electrically connected to the second electrode pad 146 through the reflective layer 140.

The distance between the second electrode pad 146 and the light emitting structure 120 may be 5 [mu] m to 30 [mu] m. If the thickness is larger than 30 mu m, the area of the second electrode pad 146 is widened in the entire device, so that the area of the active layer 123 is reduced and the amount of light can be reduced.

The height of the convex portion of the second electrode pad 146 may be higher than that of the active layer 124. Therefore, the second electrode pad 146 can reflect the light emitted in the horizontal direction of the device from the active layer 124 to the upper part, thereby improving the light extraction efficiency and controlling the directivity angle.

The first and second electrodes 182 and 186 may be formed of one selected from the group consisting of ITO (indium tin oxide), IZO (indium zinc oxide), IZTO (indium zinc tin oxide), IAZO (indium aluminum zinc oxide), IGZO ), IGTO (indium gallium tin oxide), AZO (aluminum zinc oxide), ATO (antimony tin oxide), GZO (gallium zinc oxide), IZON (IZO Nitride), AGZO ZnO, ZnO, IrOx, RuOx, NiO, RuOx / ITO, Ni / IrOx / Au or Ni / IrOx / Au / ITO, Ag, Ni, Cr, Ti, Al, Rh, Pd, Ru, Mg, Zn, Pt, Au, and Hf. However, the present invention is not limited to these materials.

The second electrode pad 146 may be formed of a conductive material. The second electrode pad 146 may have a single layer or a multi-layer structure and may include one of titanium (Ti), nickel (Ni), silver (Ag), and gold (Au). Illustratively, the second electrode pad 146 may have a structure of Ti / Ni / Ti / Ni / Ti / Au.

The central portion of the second electrode pad 146 may be recessed so that the upper surface of the second electrode pad 146 may have a concave portion and a convex portion. A wire (not shown) may be bonded to the concave portion of the upper surface. Accordingly, the bonding area can be widened and the second electrode pad 146 and the wire can be bonded more firmly.

Since the second electrode pad 146 may reflect light, the light extraction efficiency may be improved as the second electrode pad 146 is closer to the light emitting structure 120.

Irregularities may be formed on the upper surface of the light emitting structure 120. This unevenness can improve the extraction efficiency of light emitted from the light emitting structure 120. The average height of the unevenness may be different depending on the wavelength of ultraviolet light. In the case of UV-C, the height of the unevenness is about 300 nm to 800 nm and the light extraction efficiency can be improved when the average height is 500 nm to 600 nm.

3 is a cross-sectional view for explaining thickness and distance in Fig.

Referring to FIG. 3, the distance between the first electrode 182 and the first-conductivity-type semiconductor layer 122b in the first recess 125, which is the distance from the top surface of the light emitting structure 120, The distance h1 may be 300 nm to 500 nm.

The first distance h1 may be the shortest distance from the top surface of the first recess 125 to the top surface of the light emitting structure 120. [

The surface where the first electrode 182 and the first conductivity type semiconductor layer 122 are in contact may be the same surface as the interface between the first and second conductivity type semiconductor layers 122a and 122b However, it is not necessarily limited to this.

If the first distance h1 is less than 300 nm, the thickness of the first conductivity type semiconductor layer 122 becomes thin, and the current spreading may be reduced. As a result, the light flux of the semiconductor element can be lowered.

If the first distance h1 is greater than 500 nm, the first conductivity type semiconductor layer 122 may be trapped with a large amount of light. As a result, the light intensity of the semiconductor device can be lowered.

The second distance h2, which is the distance between the lower surface of the second conductivity type semiconductor layer 124 and the upper surface of the first recess 125, may be 0.7 탆 to 1 탆.

If the second distance h2 is less than 0.7 mu m, the thickness of the first conductivity type semiconductor layer 122 is too thin, so that the current diffusion characteristic is lowered, and the uniformity of the current injected into the light emitting structure 120 can be lowered. Current or heat is concentrated around the first recess 125, so that the electrical and optical characteristics and reliability of the semiconductor device may be deteriorated.

If the second distance h2 is greater than 1 mu m, the path of light emitted from the active layer 123 in the light emitting structure 120 becomes longer and the amount of light absorbed in the light emitting structure 120 increases, Can be lowered.

The angle θ1 between the lower surface of the light emitting structure 120 and the second recess 126 extending from the lower surface of the light emitting structure 120 may be 90 ° to 120 °. When the first angle? 1 between the second recess 126 and the bottom surface of the light emitting structure 120 exceeds 120 degrees, the width of the upper surface of the second recess 126 is too narrow, Gap-fill characteristics may be degraded when placed.

The second recess 126 may include a step 126a. The height h3 from the step 126a to the lower surface of the light emitting structure 120 may be equal to the height h2 from the upper surface of the first recess 125 to the lower surface of the light emitting structure 120. [

The first recess 125 and the second recess 126 may be disposed by dry etching or wet etching when a semiconductor process is applied. When the second recess 126 passing through the light emitting structure 120 is disposed through the semiconductor process, the second recess 126 is disposed through various steps because the light emitting structure 120 is thick. . When the height h3 from the step 126a to the lower surface of the light emitting structure 120 is equal to the height h2 of the light emitting structure 120 on the upper surface of the first recess 125, The number of processes can be reduced by disposing the first recess 125 and the second recess 126. And the yield and the cost of the semiconductor device can be reduced.

And the first angle [theta] 1 may be 90 [deg.] To 120 [deg.]. The first angle? 1 may be an angle between the lower surface of the light emitting structure 120 and the second recess 126 extending from the lower surface of the light emitting structure 120. However, the present invention is not limited thereto.

The second angle [theta] 2 may be 90 [deg.] To 120 [deg.]. Here, the second angle (θ2) is a light-emitting structure in the first direction, either with the step portions (126a) of the (X _1, X ₂ axis direction) or a second recess step portion (126a) containing a 126 ( 120 and the side surfaces of the first conductive semiconductor layer 122 extending to the second recess 126. In this case,

When the second angle? 2 exceeds 120, the width of the upper surface of the second recess 126 is too narrow, so that the gap-fill characteristic may be deteriorated when the reflective layer 140 is disposed.

The first angle? 1 and the second angle? 2 may be the same or different from each other. The directivity angle of the light emitting structure 120 can be controlled by adjusting the first angle? 1 and the second angle? 2 to be the same or different from each other.

When the composition of Al in the first-conductivity-type semiconductor layer 122a is increased, the current dispersion effect may be weakened. Therefore, current may be dispersed only at the vicinity of each first electrode 182, and the current density may be drastically lowered at a distance from the center of the first electrode 182. Therefore, the effective light emitting area can be narrowed.

The low current density region in which the first electrode 182 is disposed may have a low current density and may hardly contribute to light emission. Therefore, the embodiment can improve the light extraction efficiency by forming the reflection layer 140 in a region having a low current density.

However, it is inefficient to form the reflective layer 140 on the entire area of the low current density region. Therefore, it is advantageous to increase the light output by leaving only the region where the reflective layer 140 is to be formed and arranging the first electrode 182 as densely as possible in the remaining regions. However, the present invention is not limited to this configuration.

The shortest length L1 of the lower surface of the second conductivity type semiconductor layer 124 disposed between the first recess 125 and the second recess 126 may be 10 탆 to 35 탆.

The shortest distance L3 from the step 126a formed in the second-1 recess 126 to the step 126a of the adjacent second-2 recess 126 may be 45 탆 to 100 탆.

The shortest distance L2 from the central portion of the upper surface of the exposed second-1-recess 126 to the upper surface center portion of the adjacent second-second recess 126 may be 50 탆 to 110 탆.

The shortest distance L4 between the second conductive type semiconductor layers 124 disposed in the first region may be 9 占 퐉 or more and 74 占 퐉 or less. Here, the first region is a region where the second recess 126 and / or the reflective layer 140 are exposed through the upper surface of the light emitting structure 120, and the second recess 126 and / or the reflective layer 140, The surface exposed to the top surface of the light emitting structure 120 may be an interface for partitioning the plurality of first regions S1. Accordingly, the light emitting structure 120 may be divided into a plurality of first regions S1. The second recesses 126 may be disposed through the first conductive semiconductor layer 122. Referring to FIG. The upper surface of the light emitting structure 120 may be flush with the upper surface of the first insulating layer 130 disposed inside the second recess 126.

4 is an enlarged view of D in Fig.

Referring to FIG. 4, the second recess 126 may be arranged to penetrate the first conductive semiconductor layer 122. The first insulating layer 130 and the reflective layer 140 may have exposed surfaces. With this structure, the first conductivity type semiconductor layer 122 can be structurally separated between adjacent light emitting structures.

The second recess 126 may include a step 126a as previously described. The width L ₅ of the step portion 126a may be 0.5 탆 to 3 탆. The step 126a may be formed symmetrically with respect to the center of the second recess 126 disposed between the adjacent light emitting structures 120 in the first direction.

In FIG. 4A, the same step portion 126a is disposed on the x1 direction side and the x2 direction side with respect to the center of the second recess 120 in the first direction. However, for example, the x1 direction side and the x2 direction The width of the stepped portion 126a disposed on the side of the stepped portion 126a may be different.

The light emitted from the active layer 123 may scatter at the step 126a in the light emitting structure 120. [ Thus, the total internal reflection probability generated within the light emitting structure 120 is lowered, and the light efficiency of the semiconductor device can be improved.

The width L ₅ of the stepped portion 126a is equal to the width W1 from one end of the stepped portion 186 adjacent to the second electrode 186 to one end of the second recessed portion 126 extending from the other end of the stepped portion 186, (L ₆ ) may be from 1: 1.3 to 1:10.

The width L ₅ of the stepped portion 126a is equal to the width W1 from one end of the stepped portion 186 adjacent to the second electrode 186 to one end of the exposed second recess 126 adjacent to the stepped portion 126a, There is a limit that the width L ₅ of the stepped portion 126 a is reduced and the light efficiency improvement due to light scattering is reduced when the ratio of the light emitting efficiency L ₆ is smaller. Also, since the distance through which the current is injected through the electrode is long, optimal coupling between electrons and holes is not performed in the active layer 122, and the light efficiency is lowered.

The width L ₅ of the stepped portion 126a is equal to the width W1 from one end of the stepped portion 186 adjacent to the second electrode 186 to one end of the exposed second recess 126 adjacent to the stepped portion 126a, (L ₆ ) is larger than 1:10, there is a limit that the area of the light emitting region is reduced (the active layer is reduced) and the light efficiency is lowered. In addition, there is a limit that the reliability of the semiconductor device is lowered because the light emitting region is reduced and the current density is increased.

Remarks Length ratio (L5: L6) Luminous efficiency (%) Comparative Example 1 1: 1.0 77 Example 1 1: 1.3 89 Example 2 1: 5 100 Example 3 1:10 89 Comparative Example 2 1:12 77

Referring to Table 1, the width L ₅ of the step 126a is greater than the width of the exposed second recess 126a adjacent to the step 126a at one end of the step 186 adjacent to the second electrode 186 appears when the 1.3 to 1: 10 with optical efficiency over 89%:) the ratio of the width (L ₆₎ to the one end.

The width L ₅ of the step 126a is smaller than the width of the exposed second recess 126 adjacent to the step 126a at one end of the step 186 adjacent to the second electrode 186 a width (L ₆₎ to the ratio of 1: less than 1.3, or greater than 1:10 when the optical efficiency as a smaller than 80%.

Here, the light efficiency is such that the width L ₅ of the step 126a is smaller than the width of the exposed second recess 126 adjacent to the step 126a at one end of the step 186 adjacent to the second electrode 186 Is the ratio of the light emitted to the upper surface of the light emitting structure 120 when the ratio of the width L ₆ to the end is 1: 5 and the light emitted to the upper surface of the light emitting structure 140 is 100%.

Thus, in the semiconductor device of the embodiment, the first conductivity type semiconductor layer 122 is structurally separated without being connected to the first conductivity type semiconductor layer of the adjacent light emitting structure 120, The light is scattered by the portion 126a and the light extraction efficiency can be greatly improved.

5 is a partially enlarged view of Fig.

Referring to FIG. 5, the semiconductor device may include a plurality of first regions S1 defined by a second recess 126. The first electrode 182 and the second electrode 186 may be disposed in the first region S1, respectively. The first area S1 may be a polygonal shape such as a hexagon, an octagon, a square, or the like, or a shape including a curvature. However, the present invention is not limited thereto.

The semiconductor device may include a second region S2 that is a region where the first conductive semiconductor layer is exposed in the first recess 125. [ The second area S2 may be a polygonal shape such as a hexagon, an octagon, a square, or the like, or a shape including a curvature. However, the present invention is not limited thereto. The first electrode 182 may be disposed in the second region S2. The area ratio of the first region S1 to the second region S2 may be 1: 0.1 or more and 1: 0.4 or less.

Here, the second region S2 may be a region partitioned by the first recess 125. [

If the area ratio between the first region and the second region is less than 1: 0.1, the area of the first electrode 182 disposed inside the first recess 125 may be narrowed, which may raise the operating voltage.

If the area ratio between the first region and the second region is more than 1: 0.4, the area of the active layer 123 and the area of the second conductivity type semiconductor layer becomes narrow, so that the luminous flux emitted from the light emitting structure may decrease .

6A to 6F are views showing a method of manufacturing a semiconductor device according to an embodiment of the present invention.

6A to 6F, the method includes the steps of disposing the light emitting structure on the growth substrate 1, removing a portion of the light emitting structure to dispose the first recess and the second recess, Forming a first electrode on the first conductive type semiconductor layer, a second electrode on the upper surface of the second conductive type semiconductor layer, a first insulating layer, disposing a reflective layer on the first insulating layer, Disposing a bonding layer on the second insulating layer, and disposing the substrate 170 on the bonding layer. Next, the step of removing the growth substrate 1 and etching the first conductivity type semiconductor layer to a predetermined thickness range may be included.

6A, the first conductive semiconductor layer 122, the active layer 123, and the second conductive semiconductor layer 124 are sequentially disposed on the growth substrate 1 to form the light emitting structure 120 .

The first conductivity type semiconductor layer 122 includes a first conductivity type semiconductor layer 122a in contact with the growth substrate 1 and a first conductivity type semiconductor layer 122b on the first conductivity type semiconductor layer 122a, And the semiconductor layer 122b. The composition of the first conductivity type semiconductor layer 122a may be higher than that of the first conductivity type semiconductor layer 122b.

A buffer layer (not shown) may be further provided between the first conductivity type semiconductor layer and the substrate 170. The buffer layer (not shown) may mitigate lattice mismatch between the first conductivity type semiconductor layer 122, the active layer 123, and the second conductivity type semiconductor layer 124 and the substrate 170. The buffer layer may be a combination of Group III and Group V elements or may include any one of GaN, InN, AlN, InGaN, AlGaN, InAlGaN, and AlInN. The buffer layer may be doped with a dopant, but is not limited thereto.

The first conductive type semiconductor layer 122, the active layer 123 and the second conductive type semiconductor layer 124 may be formed by a metal organic chemical vapor deposition (MOCVD) method, a chemical vapor deposition (CVD) method, a plasma (PECVD), molecular beam epitaxy (MBE), hydride vapor phase epitaxy (HVPE), sputtering, or the like But is not limited thereto.

Referring to FIG. 6B, a part of the second conductivity type semiconductor layer 124, the active layer 123, and the first conductivity type semiconductor layer 122 may be removed by a first etching process. The etching may be performed up to a part of the first conductivity type semiconductor layer 122. The second conductivity type semiconductor layer 124, the active layer 123, and the first conductivity type semiconductor layer 122 may be exposed by etching.

Referring to FIG. 6C, a part of the first conductive type semiconductor layer 122 may be removed to the upper surface of the first conductive type semiconductor layer 122a by the second etching. The second etching may be performed up to a part of the first conductive type semiconductor layer 122a. As a result, the growth substrate 1 is not exposed. The second etching may expose a part of the lower region of the first-conductivity-type semiconductor layer 122a. The first conductivity type semiconductor layer 122, the active layer 123, and the second conductivity type semiconductor layer 124 may be exposed through the first etching and the second etching. The light emitting structure 120 may have two mesa-etched structures.

Referring to FIG. 6D, the first insulating layer 130 may be located on the first conductive semiconductor layer 122, the active layer 123, and the second conductive semiconductor layer 124. The first electrode 182 may be deposited on the surface in contact with the first-conductivity-type semiconductor layer 122b. The second electrode 186 may be deposited on the second conductive semiconductor layer 124.

The first electrode 182 and the second electrode 186 may be formed of an opaque metal such as Ag, Ni, Al, Rh, Pd, Ir, Ru, Mg, Zn, Pt, Au or Hf. In this case, since the light emitting area is reduced by the area of the first electrode 182, the size of the first electrode 182 may be preferably small.

The first electrode 182 and the second electrode 186 may be formed by a conventional electrode forming method such as sputtering, coating, or vapor deposition. A reflective layer and an ohmic layer may be further formed when the first electrode 182 and the second electrode 186 are formed.

The first recess 125 is formed between the first electrode 182 and the second electrode 186 and the second recess 126 is formed between the first conductive semiconductor layer And between the exposed upper surfaces of the second conductivity type semiconductor layer 124 in the first conductive semiconductor layer 122a.

The first electrode 182 and the second electrode 186 may be ohmic electrodes of the first electrode 182 and the second electrode 186. The first and second electrodes 182 and 186 may be formed of one selected from the group consisting of ITO (indium tin oxide), IZO (indium zinc oxide), IZTO (indium zinc tin oxide), IAZO (indium aluminum zinc oxide), IGZO ), IGTO (indium gallium tin oxide), AZO (aluminum zinc oxide), ATO (antimony tin oxide), GZO (gallium zinc oxide), IZON (IZO Nitride), AGZO ZnO, ZnO, IrOx, RuOx, NiO, RuOx / ITO, Ni / IrOx / Au or Ni / IrOx / Au / ITO, Ag, Ni, Cr, Ti, Al, Rh, Pd, Ru, Mg, Zn, Pt, Au, and Hf. However, the present invention is not limited to these materials.

The reflective layer 140 may be formed on the second recess 126 and the second electrode 186. However, the reflective layer 140 may be electrically isolated from the first electrode 182. The reflective layer 140 may be disposed below the second electrode 186 and may be electrically connected to the second electrode 186.

The second insulating layer 150 may be disposed under the reflective layer 140 and the first recess 125. With such a configuration, the reflection layer 140 and the first electrode 182 can be electrically insulated.

Referring to FIG. 6E, the bonding layer 160 may be disposed under the second insulating layer 150. The bonding layer 160 may be disposed under the second insulating layer 150 and under the first electrode 182 and may be electrically connected to the first electrode 182.

The substrate 170 may be formed on the bonding layer 160. And the growth substrate 1 can be removed. The method of removing the substrate 170 is not particularly limited. For example, the growth substrate 1 may be removed by an LLO (Laser Lift-Off) process, but the present invention is not limited thereto.

The bonding layer 160 can bond the light emitting structure 120 to the substrate 170 disposed under the light emitting structure 120

Referring to FIG. 6F, the upper surface of the first insulating layer 130 and the upper surface of the light emitting structure 120 may have various arrangements depending on the etching. First, the first insulating layer 130 may be flush with the upper surface of the light emitting structure 120.

That is, the upper surface of the light emitting structure 120 and the upper surface of the reflective layer 140 may be the same surface to form a flat surface through etching. However, in the actual process, the first insulating layer 130 may partially remain to protect the first insulating layer 130.

The semiconductor device is constituted by a package and can be used for curing resin, resist, SOD or SOG. Alternatively, the semiconductor device may be used for therapeutic medical use or for sterilizing air purifiers, water purifiers, and the like.

Further, the semiconductor device may be used as a light source of an illumination system, or as a light source of a video display device or a lighting device. That is, semiconductor devices can be applied to various electronic devices arranged in a case to provide light. Illustratively, when a semiconductor device and an RGB phosphor are mixed and used, white light with excellent color rendering (CRI) can be realized.

The above-described semiconductor device is composed of a light emitting device package and can be used as a light source of an illumination system, for example, as a light source of a video display device or a lighting device.

When used as a backlight unit of a video display device, it can be used as an edge type backlight unit or as a direct-type backlight unit. When used as a light source of a lighting device, it can be used as a regulator or a bulb type. It is possible.

The light emitting element includes a laser diode in addition to the light emitting diode described above.

The laser diode may include the first conductivity type semiconductor layer, the active layer and the second conductivity type semiconductor layer having the above-described structure, like the light emitting element. Then, electro-luminescence (electroluminescence) phenomenon in which light is emitted when an electric current is applied after bonding the p-type first conductivity type semiconductor and the n-type second conductivity type semiconductor is used, And phase. That is, the laser diode can emit light having one specific wavelength (monochromatic beam) with the same phase and in the same direction by using a phenomenon called stimulated emission and a constructive interference phenomenon. It can be used for optical communication, medical equipment and semiconductor processing equipment.

As the light receiving element, a photodetector, which is a kind of transducer that detects light and converts the intensity of the light into an electric signal, is exemplified. As such a photodetector, a photodiode (e.g., a PD with a peak wavelength in a visible blind spectral region or a true blind spectral region), a photodiode (e.g., a photodiode such as a photodiode (silicon, selenium), a photoconductive element (cadmium sulfide, cadmium selenide) , Photomultiplier tube, phototube (vacuum, gas-filled), IR (Infra-Red) detector, and the like.

In addition, a semiconductor device such as a photodetector may be fabricated using a direct bandgap semiconductor, which is generally excellent in photo-conversion efficiency. Alternatively, the photodetector has a variety of structures, and the most general structure includes a pinned photodetector using a pn junction, a Schottky photodetector using a Schottky junction, and a metal-semiconductor metal (MSM) photodetector have.

The photodiode, like the light emitting device, may include the first conductivity type semiconductor layer having the structure described above, the active layer, and the second conductivity type semiconductor layer, and may have a pn junction or a pin structure. The photodiode operates by applying reverse bias or zero bias. When light is incident on the photodiode, electrons and holes are generated and a current flows. At this time, the magnitude of the current may be approximately proportional to the intensity of the light incident on the photodiode.

A photovoltaic cell or a solar cell is a type of photodiode that can convert light into current. The solar cell, like the light emitting device, may include the first conductivity type semiconductor layer, the active layer and the second conductivity type semiconductor layer having the above-described structure.

In addition, it can be used as a rectifier of an electronic circuit through a rectifying characteristic of a general diode using a p-n junction, and can be applied to an oscillation circuit or the like by being applied to a microwave circuit.

In addition, the above-described semiconductor element is not necessarily implemented as a semiconductor, and may further include a metal material as the case may be. For example, a semiconductor device such as a light receiving element may be implemented using at least one of Ag, Al, Au, In, Ga, N, Zn, Se, P, or As, Or may be implemented using a doped semiconductor material or an intrinsic semiconductor material.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, but, on the contrary, It will be understood that various modifications and applications are possible. For example, each component specifically shown in the embodiments can be modified and implemented. It is to be understood that all changes and modifications that come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.

120: light emitting structure
122: a first conductivity type semiconductor layer
122a: the 1-1-conductivity type semiconductor layer
122b: a first-conductivity-type semiconductor layer
123: active layer
124: second conductive type semiconductor layer
125: 1st recess
126: Second recess
130: first insulating layer
140: reflective layer
146: second electrode pad
150: second insulating layer
160: bonding layer
170: substrate
182: first electrode
186: second electrode

Claims (11)

An active layer disposed between the first conductivity type semiconductor layer and the second conductivity type semiconductor layer, the second conductivity type semiconductor layer, and the active layer, the first conductivity type semiconductor layer, the second conductivity type semiconductor layer, A first recess disposed to a partial region of the one conductivity type semiconductor layer; And a second recess penetrating the first conductive semiconductor layer;
A first electrode disposed in the first recess and electrically connected to the first conductive semiconductor layer; And
And a reflective layer disposed under the second conductive type semiconductor layer.
The method according to claim 1,
And the second recess includes a stepped portion.
3. The method of claim 2,
The width of the stepped portion is set such that the ratio of the width from one end of the stepped portion adjacent to the second electrode to one end of the exposed second recess adjacent to the stepped portion
3. The method of claim 2,
Wherein a distance between an upper surface of the second electrode and the stepped portion is equal to a distance between an upper surface of the second electrode and a surface of the first electrode in contact with the first conductive type semiconductor layer.
The method according to claim 1,
Wherein the thickness of the reflective layer is 0.5 占 퐉 to 1 占 퐉.
The method according to claim 1,
And a second electrode pad electrically connected to the reflective layer.
The method according to claim 1,
And a second electrode disposed between the second conductivity type semiconductor layer and the reflective layer.
The method according to claim 1,
And the reflective layer is electrically connected to the second electrode.
The method according to claim 1,
And a bonding layer disposed under the first recess and the first electrode.
10. The method of claim 9,
And a substrate disposed under the bonding layer and electrically connected to the bonding layer.
A semiconductor element according to any one of claims 1 to 10; And
And a case accommodating the semiconductor element.

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