KR20170136837A - Semiconductor device - Google Patents

Abstract

An embodiment of the present invention provides a light emitting device which includes: a semiconductor structure which includes a first conductive semiconductor layer, an active layer, and a second conductive semiconductor layer, and has a through hole formed from the second conductive semiconductor layer to a part of the first conductive semiconductor layer and the active layer; a first ohmic layer in contact with the first conductive semiconductor layer; a second ohmic layer in contact with the second conductive semiconductor layer; and a support substrate which is arranged on the lower side of a light emitting structure and is electrically connected to the first ohmic layer through a bonding layer, wherein the bonding layer has a protrusion part arranged toward the first ohmic layer and the lateral side of the protrusion part has an inclination of 10 to 40 degrees with respect to the bottom surface of the bonding layer. Accordingly, the present invention can prevent a crack or void.

Description

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

BACKGROUND OF THE INVENTION 1. Field of the Invention [0002] The present invention relates to a semiconductor device, and more particularly, to removing cracks and voids that may occur in a semiconductor device.

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.

The light emitting device includes a light emitting structure including a first conductivity type semiconductor layer, an active layer, and a second conductivity type semiconductor layer, wherein the first conductivity type semiconductor layer and the second conductivity type semiconductor layer have a first electrode and a second electrode, And can be electrically connected.

Since the first electrode and the second electrode have poor contact properties with the first conductivity type semiconductor layer and the second conductivity type semiconductor layer made of semiconductors, the first and second ohmic layers and the second ohmic layer can be disposed, respectively, have.

In order to contact the first electrode and the second electrode or the first and second ohmic layers with the second conductivity type semiconductor layer, a part of the light emitting structure is subjected to mesa etching to form a through hole It is possible.

At this time, a layer such as a bonding layer may be disposed inside the through hole so as to be protruded. In the bonding process with the conductive supporting substrate and other processes, stress is applied due to external heat or pressure, Thus, cracks and voids may occur in each layer, and materials and other materials of the bonding layer may leak out into cracks or voids.

The embodiment attempts to prevent cracks and voids that may occur inside the semiconductor device.

An embodiment includes a semiconductor structure including a first conductivity type semiconductor layer, an active layer, and a second conductivity type semiconductor layer, the second conductivity type semiconductor layer, the active layer, and a portion of the first conductivity type semiconductor layer; A first ohmic layer contacting the first conductive semiconductor layer; A second ohmic layer contacting the second conductive semiconductor layer; And a supporting substrate disposed under the light emitting structure and electrically connected to the first ohmic layer through a bonding layer, wherein the bonding layer has protrusions disposed in the direction of the first ohmic layer, Provides a light emitting device having an inclination of 10 to 40 degrees with respect to the bottom surface of the bonding layer.

The protruding portion of the bonding layer may be partially overlapped with the through-hole.

The height of the protrusion may be equal to or less than the thickness of the insulating layer in the through-hole.

The width of the inclined side surface of the projecting portion may be larger than the height of the projecting portion.

Another embodiment includes a semiconductor structure including a first conductivity type semiconductor layer, an active layer, and a second conductivity type semiconductor layer, and the second conductivity type semiconductor layer, the active layer, and a part of the first conductivity type semiconductor layer, ; A first ohmic layer contacting the first conductive semiconductor layer; A second ohmic layer contacting the second conductive semiconductor layer; And a support substrate disposed under the light emitting structure and electrically connected to the first ohmic layer through a bonding layer, wherein the bonding layer has protrusions disposed in the direction of the first ohmic layer, And a groove is formed in the region.

The protrusion may further include an upper surface and a side surface inclined from the upper surface in the groove direction.

The protrusion may further include a bottom surface formed in an outer area of the groove.

The height of the bottom surface may be higher than the height of the groove and lower than the height of the upper surface.

In the semiconductor device according to the embodiment, the inclination of the side surface of the projecting portion of the bonding layer is gentle, cracks and voids may not be generated even when an external force acts in the joining process of the supporting substrate and the like. The amount of flow to the outside can be small.

Further, grooves are formed in the peripheral region of the protruding portion of the bonding layer, so that even if the bonding layer and the first ohmic layer are leaked out, they can be prevented from mixing or coming into contact with each other.

1 is a view showing a first embodiment of a semiconductor device,
FIG. 2 is a detailed view of a portion A of FIG. 1,
FIG. 3 is a view showing another embodiment of the portion A of FIG. 1,
4 is a view showing a package in which semiconductor elements are arranged.

BRIEF DESCRIPTION OF THE DRAWINGS The above and other objects, features and advantages of the present invention will be more apparent from the following detailed description taken in conjunction with the accompanying drawings, in which: FIG.

In the description of the embodiment according to the present invention, in the case of being described as being formed "on or under" of each 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.

The semiconductor device may include various electronic devices such as a light emitting device and a light receiving device. The light emitting device and the light receiving device may include the first conductivity type semiconductor layer, the active layer, and the second conductivity type semiconductor layer.

The semiconductor device according to this embodiment may be a light emitting device.

The light emitting device emits light by recombination of electrons and holes, and the wavelength of the light is determined by the energy band gap inherent to the material. Thus, the light emitted may vary depending on the composition of the material.

FIG. 1 is a view showing a first embodiment of a semiconductor device, and FIG. 2 is a detailed view of a portion A in FIG.

The semiconductor device 100 according to the present embodiment includes a semiconductor structure 120 including a first conductivity type semiconductor layer 122, an active layer 124 and a second conductivity type semiconductor layer 126, And a second ohmic layer 146 in contact with the first ohmic layer 142 and the second conductive semiconductor layer 126 that are in contact with the semiconductor layer 122. The light emitting structure 120 and the like include the support substrate 170 As shown in FIG.

The first conductive semiconductor layer 122 may be formed of a compound semiconductor such as Group III-IV or II-V, and may be doped with a first conductive dopant. The first conductive semiconductor layer 122 may be a semiconductor material having a composition formula of Al _x In _y Ga _(1-xy) N (0? X? 1, 0? _Y? 1, 0? _X + y? , GaN, InAlGaN, AlGaAs, GaP, GaAs, GaAsP, and AlGaInP.

In particular, when the first conductivity type semiconductor layer 122 is made of Al _x Ga _(1-x) N (0.4 _x 0.8), light in the UVB or UVC wavelength region can be emitted from the active layer.

When the first conductive semiconductor layer 122 is an n-type semiconductor layer, the first conductive dopant may include n-type dopants such as Si, Ge, Sn, Se, and Te. The first conductive semiconductor layer 122 may be formed as a single layer or a multilayer, but is not limited thereto.

The active layer 124 may include any one of a single well structure, a multi-well structure, a single quantum well structure, a multi quantum well (MQW) structure, a quantum dot structure or a quantum wire structure.

InGaN / InGaN, InGaN / InGaN, AlGaN / GaN, InAlGaN / GaN, GaAs (InGaAs), and AlGaN / AlGaN / InGaN / GaN, , / AlGaAs, GaP (InGaP) / AlGaP, but the present invention is not limited thereto. The well layer may be formed of a material having an energy band gap smaller than the energy band gap of the barrier layer.

The second conductivity type semiconductor layer 126 may be a semiconductor material having a composition formula of In _x Al _y Ga _{1 -x- y} N (0? X? 1, 0? _Y? 1, 0? _X + , AlGaN, GaN, AlInN, AlGaAs, GaP, GaAs, GaAsP, and AlGaInP.

When the second conductive semiconductor layer 126 is a p-type semiconductor layer, the second conductive dopant may be a p-type dopant such as Mg, Zn, Ca, Sr, or Ba. The second conductive semiconductor layer 126 may be formed as a single layer or a multilayer, but the present invention is not limited thereto.

An electron blocking layer (not shown) may be disposed between the active layer 124 and the second conductivity type semiconductor layer 126, and the electron blocking layer may be made of AlGaN, for example.

When the electron blocking layer is made of AlGaN and the second conductivity type semiconductor layer 126 is made of GaN, the injection of holes may not be smooth due to the low electric conductivity of AlGaN. The problem of GaN, which has relatively high electric conductivity, Can be solved.

Holes are formed in the light emitting structure 120 from the second conductive semiconductor layer 126 through the active layer 124 to a portion of the first conductive semiconductor layer 122, The first ohmic layer 142 may be disposed on the second insulating layer 122. Although one through hole is shown in FIG. 1, a plurality of through holes may be disposed in the light emitting device 100, and the shape and size of each through hole may be substantially the same.

The upper surface of the first conductivity type semiconductor layer 122 may have irregularities, which may improve extraction efficiency of light emitted from the light emitting device 100. The active layer 124, the electron blocking layer 130 and the second conductivity type semiconductor layer 126 may be wider from the first conductivity type semiconductor layer 122 to the active layer 124. In the mesa etching process, This is because the width of the substructure can be etched more widely.

A capping layer 150 may be disposed on a second region of the second conductivity type semiconductor layer 126 to surround a portion of the lower surface and side surfaces of the second ohmic layer 146, And may be made of a conductive material, for example, a metal, and may support the second ohmic layer 146 and electrically connect the second electrode 166 and the second ohmic layer 146.

The first ohmic layer 142 is formed on the exposed surface of the second conductivity type semiconductor layer 126 and the first ohmic layer 142 and the second ohmic contact layer 140 so that the second ohmic layer 146 and the capping layer 150 are not electrically connected. The first insulating layer 130 may be disposed around the capping layer 150.

2, the first ohmic layer 142 is disposed on the first conductive type semiconductor layer 122 exposed from the exposed portion of the first conductive type semiconductor layer 122 in the upper region of the through hole, A protrusion may be formed in the direction of the through hole. Depending on the shape of the supporting substrate 170, the bonding layer 160 may also have protrusions in the direction of the through holes.

The bonding layer 160 may be made of a conductive material and may be formed of a metal such as gold (Au), tin (Sn), indium (In), aluminum (Al), silicon (Si) ) And copper (Cu), or an alloy thereof.

The support substrate 170 may be made of a conductive material, for example, a metal or a semiconductor material. The material of the support substrate 170 may be a metal having a high electrical conductivity or a high thermal conductivity, and may be formed of a material having a high thermal conductivity so that heat generated during operation of the light emitting device can be sufficiently diffused. For example, a material selected from the group consisting of silicon (Si), molybdenum (Mo), silicon (Si), tungsten (W), copper (Cu), and aluminum (Al) In addition, gold (Au), copper alloy (Cu Alloy), nickel (Ni), copper-tungsten (Cu-W), carrier wafers (e.g., GaN, Si, Ge, GaAs, ZnO, SiGe, SiC, SiGe, Ga ₂ O _3, etc.), and the like.

2, the side surface of the protruding region of the bonding layer 160 is inclined at an angle of 10 to 40 degrees with respect to the bottom surface of the bonding layer 160, and the two sides of the protruded region of the bonding layer 160 The angles? 1 and? 2 formed by the sides of the bonding layer 160 with respect to the bottom surface of the bonding layer 160 may be equal to each other.

If the angles? 1 and? 2 are larger than 40 degrees, cracks or voids may occur in the process described later between the protruding portion of the bonding layer 160 and the first insulating layer 130, The width w0 for the protrusion 160 to protrude in the direction of the through hole can be excessively increased.

2, the thickness h0 of the first insulating layer 130 may be 1 micrometer and the height h1 of the protruding region of the bonding layer 160 may be greater than the height h1 of the first insulating layer 130, For example, from 500 nanometers to 1,000 nanometers.

The width w0 of the side surface inclined in the protruding region of the bonding layer 160 may be greater than the height h1 of the protruding region described above and may be, for example, from 1 micrometer to 3 micrometers .

2, the protruded portion of the bonding layer 170 is not inserted into the through hole, but actually a part of the protruded portion of the bonding layer 170 is inserted into the through hole as shown in FIG. 1, Can be overlapped with the structure 120 in the horizontal direction.

The first insulating layer 130 is provided in a region between the first ohmic layer 142 and the second ohmic layer 146 and between the capping layer 150 and the bonding layer 160 in the lower region of the light emitting structure 120 , It is possible to prevent an electrical short circuit between the first conductivity type semiconductor layer 122 and the second conductivity type semiconductor layer 126.

The second insulating layer 180 may be disposed on the upper surface and the side surface of the light emitting structure 120 and the upper surface of the capping layer 150. The second insulating layer 180 may be formed on the upper surface of the capping layer 150, The second electrode 166 may be disposed on the capping layer 150, which is partially opened and exposed, and the second insulating layer 180 on the periphery.

The first insulating layer 130 and the second insulating layer 180 may be made of the same material and may be made of an oxide or nitride. More specifically, the first insulating layer 130 and the second insulating layer 180 may be formed of a silicon oxide (SiO ₂ ) And an aluminum oxide layer.

A stress is applied to the lower region of the light emitting structure 120 in the bonding process of the supporting substrate 170 so that the first insulating layer 130 and the bonding layer 160 are bonded to each other, A crack may be generated. However, the light emitting device according to the above-described embodiment can be formed with a gentle slope on the side surface of the projecting portion of the bonding layer 160, thereby preventing occurrence of voids and cracks. Further, the inclination of the side surface of the bonding layer 160 is gentle, so that the amount of the material flowing out of the bonding layer 160 may be small even if the material or other material flows out.

3 is a view showing another embodiment of the portion A in Fig.

The semiconductor device shown in Fig. 3 is the same as the semiconductor device shown in Figs. 1 and 2, and the different parts are mainly described. In the semiconductor device according to the present embodiment, a groove may be formed in the edge region of the protrusion of the bonding layer 160.

The bonding layer 160 includes a top surface 160a, a side surface 160b inclined with respect to the top surface 160a, a groove 160c disposed around the side surface 160b, And an interface 160d between the bottom surface 160e and the groove 160c may be disposed perpendicular to the bottom surface 160e and the groove 160c .

The height of the bottom surface 160e is higher than the height of the groove 160c and is lower than the height of the top surface 160a so that when the material of the first ohmic layer 142 flows out, Can be prevented from overflowing. The upper surface 160a and the side surface 160b may protrude from the groove 160c and may be referred to as protruding portions of the bonding layer 160. [

Stress is applied to the lower region of the light emitting structure 120 in the bonding process of the supporting substrate 170 as described above and the stress is applied to the first insulating layer 130 and the bonding layer 160 The material of the first ohmic layer 142 may flow into the voids or cracks. However, in the light emitting device according to the present embodiment, a groove is formed in the peripheral region of the protruding portion of the bonding layer 160 Even if the material of the first ohmic layer 142 flows out, it can be accommodated in the groove 160c. Therefore, it is possible to prevent the material of the bonding layer 160 and the first ohmic layer 142 from mixing or contacting with the capping layer 150 or the like.

4 is a view showing a package in which the semiconductor device of FIG. 2 is disposed.

The light emitting device package 300 according to the embodiment includes a package body 310, a first electrode unit 321, a second electrode unit 322, and a light emitting device 200.

The package body 310 may be made of an insulating material having a cavity, and may include, for example, PPA (polypthalamide) resin, silicon-based material, or the like.

The electrode portion 321 and the second electrode portion 322 may be disposed on the package body 310 and partly on the bottom surface of the cavity, respectively.

The light emitting device 300 may be the light emitting device described above and may be disposed on the first electrode unit 321 and electrically connected to the second electrode unit 322 through the wire 330.

The molding part 350 is disposed around the light emitting device 200 and the wire 330 to protect the light emitting device 200 and the wire 330.

The molding part 350 may include a phosphor (not shown). The phosphor may be a YAG-based phosphor, a nitride-based phosphor, a silicate, or a mixture thereof, but is not limited thereto.

The light emitting device may include a light emitting device package and may be used as a light source of an illumination system, for example, as a light source of a video display device, a lighting device, or the like. The device can be used for sterilizing devices such as water purifiers, air cleaners, and medical devices.

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 bulb type. It is possible.

The light emitting device includes a laser diode in addition to the light emitting diode described above, and the structure of the light emitting device according to the embodiment can be applied to other semiconductor devices such as a laser diode.

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 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.

100, 200: Semiconductor device 120: Light emitting structure
130: first insulating layer 142: first ohmic layer
146: second ohmic layer 150: capping layer
160: bonding layer 160a: upper surface
160b: side surface 160c: groove
160d: boundary surface 160e: bottom surface
170: supporting substrate 180: second insulating layer
300: semiconductor device package

Claims (8)

A semiconductor structure including a first conductivity type semiconductor layer, an active layer, and a second conductivity type semiconductor layer, wherein the second conductivity type semiconductor layer has a through hole from the second conductivity type semiconductor layer to the active layer and a part of the first conductivity type semiconductor layer;
A first ohmic layer contacting the first conductive semiconductor layer;
A second ohmic layer contacting the second conductive semiconductor layer; And
And a support substrate disposed under the light emitting structure and electrically connected to the first ohmic layer through a bonding layer,
Wherein the bonding layer has protrusions in the direction of the first ohmic layer, and the side surfaces of the protrusions have inclination of 10 to 40 degrees with respect to the bottom surface of the bonding layer. The method according to claim 1,
And the protruding portion of the bonding layer partially overlaps the through-hole. The method according to claim 1,
Wherein a height of the protrusion is equal to or smaller than a thickness of the insulating layer in the through hole. The method according to claim 1,
Wherein a width of an inclined side surface of the protrusion is larger than a height of the protrusion. A semiconductor structure including a first conductivity type semiconductor layer, an active layer, and a second conductivity type semiconductor layer, wherein the second conductivity type semiconductor layer has a through hole from the second conductivity type semiconductor layer to the active layer and a part of the first conductivity type semiconductor layer;
A first ohmic layer contacting the first conductive semiconductor layer;
A second ohmic layer contacting the second conductive semiconductor layer; And
And a support substrate disposed under the light emitting structure and electrically connected to the first ohmic layer through a bonding layer,
Wherein the bonding layer has protrusions in the direction of the first ohmic layer, and the protrusions have grooves in the outer area. 6. The method of claim 5,
Wherein the projecting portion further comprises an upper surface and a side surface inclined from the upper surface in the groove direction. The method according to claim 6,
Wherein the projecting portion further comprises a bottom surface formed in an outer region of the groove. 8. The method of claim 7,
Wherein a height of the bottom surface is higher than a height of the groove and lower than a height of the upper surface.

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